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Boston Medical Library 
in the Francis A. Countway 
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F.R.C. P., Medical Officer in Charge of the Electrical Department in 
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M.D., D.P.H. (Lond. Univ.), Lecturer on Public Health at St. George's 
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The whole of the matter has been carefully revised in 
this edition and sixty fresh pages have been added. 

The utilisation of current from the mains for medical 
and surgical purposes is now given a separate chapter. 
The chapter on statical electricity has been re- written 
and brought up-to-date. The uses of the electric bath 
and arm-bath are treated more fully than before, and 
a short chapter on X ray work has been added at the 
end of the book. 

I wish to record my indebtedness to the Archives 
d'electvicite medicale, and to Professor Bergonie, its able 
editor, for many valuable papers and references. 

In an appendix will be found a Hst of towns and 
places having a public electric light supply, with some 
* details of the character of the current furnished. 

6i Wimpole Street. 

May, igoo. 

Digitized by the Internet Archive 

in 2010 with funding from 

Open Knowledge Commons and Harvard Medical School 




Origin of the word Electricity. Dr. Gilbert of Colchester. Early 
medical writers. Remak and Duchenne. Position of electri- 
city in medicine Pages i — 6 


Fundamental Experiments and Definitions. 

Fundamental Experiments. Hypotheses of Fluids. Electroscopes. 
Conduction. Electric Quantity. Electromotive Force. Poten- 
tial. Electrometers. Electric Density. Capacity. Condensers. 
Leyden Jar. Contact electromotive force. Simple Voltaic cell 
or battery. Oersted's experiment. Magnetic field. Galvano- 
meters. Electromotive force. Resistance. Ohm's Law. 
Practical units. Specific resistance. Measurement of resist- 
ance. Electrolysis. Resistance of an electrolyte. Electro- 
magnetic induction Pages 7 — 47 



Essentials of a good battery. Electromotive force ot cells. Capa- 
city of cells. Polarization. The Smee, Bichromate, Daniel), 
Grove and Bunsen batteries. Leclanche battery. Dry batteries. 


Chloride of silver battery. Oxide of copper batter)'. Sulphate 
of mercury battery. Stohrer's battery. Accumulators. Table 
of batteries. Choice of a battery. Care of a battery 

Passes 48 — 80 


Dynamo Electricity. 

The Dynamo Machine. Current Generators. The electric lighting 
mams. Direct and alternating current. Current from the main 
for medical and surgical applications. Regulation by resist- 
ances. Transformers. Dynamotors and motor dynamos 

Pages 81 — 103 


The Induction Coil. Conducting Wires. Binding Screws. Elec- 
trodes. Current Collectors. Commutators. Regulation of 
Current. Galvanometers .... Pages 104 — 150 


Electricity of High Potential. Statical 

Electricity of High Potential, Statical Electricity. Description of 
instruments. The Holtz machine. Wimshurst's machine. 
Conductors and electrodes. Treatment by charging. The static 
breeze. Treatment by sparks. The Leyden jar. Morton's 
method. Effects of static treatment. High frequency and high 
potentials. D'Arsonval's experiments. Their physiological and 
therapeutic effects Pages 151 — 190 




The resistance of the body. Diffusion of current in the body. The 
action of electrical currents on living tissues. The motor nerves 
and muscles. Unstriped muscle. Sensory nerves. Refreshing 
action. Trophic effects. Electrical osmosis. Lethal effects. 
Magnetism Pages 191 — 224 



Electrical testing. The motor points. Relation of spinal nerve- 
roots to muscles. Morbid changes in the electrical reactions. 
The reaction of degeneration. The sensory nerves. Nerves 
of the special senses. The auditory nerve . Pages 225 — 260 


General Therapeutics. 

Effects of electricity. Choice of current. Strength of current. 
Choice of pole. Methods. " General faradisation." "Galvano- 
faradisation." Galvanisation of the cervical sympathetic. Cen- 
tral galvanisation. Self treatment by patients Pages 261 — 281 


The Electric Bath. 

The bath. Accessory apparatus. The resistance of the bath. The 
mode of application. The use of the electric light mains. Hot 
air or vapour electric bath. Uses in chronic rheumatoid 
arthritis. Gout. Sciatica and lumbago. Nervous affections. 
Rickets. Anaemia. Raynaud's disease . Pages 282 — 313 



Electrical Treatment in Diseases of the Brain 
AND THE General Neuroses. 

Cerebral disease. Hemiplegia. Epilepsy. Chorea. Hysteria. 
Hypochondriasis and neurasthenia. Insomnia. Tremors and 
spasm. Writer's cramp. Tetany. Exophthalmic goitre. 
Migraine and headache. Mental diseases . Pages 314—333 


The Spinal Cord and Nerves. 

The spinal cord. Treatment of paralysis. Infantile paralysis. Pro- 
gressive muscular atrophy. Injuries of nerves. Special nerve 
injuries. Neuritis. Neuralgia. Sciatica. Anaesthesia. Nerves 
of special senses Pages ^^^ — 407 


Other Conditions requiring Electrical Treatment. 

The relief of congestion. Joint affections. Inflammatory exuda- 
tions. Ascites. Corneal opacities. The urinary organs. 
Nocturnal incontinence. Constipation. Sexual disorders. 
Cutaneous affections. Galactagogue effects. Guinea worm. 
Suspended animation. Electricity as a test of death. 

Pages 408 — 431 



The laws of electrolysis. Actions in living tissues. Uses in surgery. 
Removal of hairs. Moles and Warts. Naevus. Port wine 
mark. Aneurysm. Stricture of the urethra, of the oesophagus, 


of the rectum, of the Eustachian tube. Electrolysis in fibro- 
myoma. Dr. Apostoli's methods. Extra-uterine foetation. 
Cancer Pages 432—467 


Cautery and Lighting Instruments. The 

The galvano-cautery. Batteries for cautery purposes. Accumu- 
lators. Wires and leads. Lampr. Batteries for lamps. The 
use of electric light mains. Rheostats. The cystoscope. The 
panelectroscope. The electro-magnet . Pages 468 — 487 

The Rontgen Rays. 

The Crookes' tube. The sources of electricity. The static machine. 
Management of coils. Screen work. Photography. Localisa- 
tion of foreign bodies. Diseases of the heart and lungs. 

Pages 488—507 


Lists of towns and districts with continuous and alternating current 
supplies Pages 509 — 572 

Of the motor points and the cutaneous nerves . Pages 513 — 525 

Index . . . . . , . . . Pages 527 — 532 




I. Stewart's gold leaf electroscope 


2. Leyden jar . , . . 


3. Single voltaic cell . . . . 

. 27 

4. Lines of force of a bar magnet . . . 


5. Typical circuit . . . . 

• 35 

6. Cells arranged in series . . . . 


7. Cells arranged in parallel . . . 

• 52 

8. Two-fluid cell . . . 


g. Bichromate battery .... 

• 57 

10. Leclanche cell . . . . . 


II. Hellesen's dry cell .... 

• 63 

12. Edison-Lalande cell . . 


13. Stohrer's battery . . 

. 66 

14. Accumulator in glass vessel 


15. Five-cell lithanode cell with detachable lamp 

• 71 

16. Lithanode testing cell . . . . 


17. Schall's combined battery 

• 75 

18. Combined medical battery . . . . 


ig. Series wound dynamo 

■ 83 

20. Shunt wound dynamo . . . . 


21. Vandervell's gas engine 

■ 87 

22. Plan of resistance in shunt to a patient 


23. Resistance in shunt 

• 95 

24. Charging an accumulator from the electric light mains 


25. Lamp resistance for charging secondary cells from the 

mains 97 

26. Graduated transformer . . . . 


27. Woakes' transformer 

. 100 

28. Motor dynamo . . ... 


2g. Dynamotor .... 

. 102 

30. Arrangement of wires in an induction coil 


31. Induction coil .... 

. 108 

32. Induction coil . . . . . 




33. Ewald's coil ..... 114 

34. Graphic representation of a steadily varying electromotive 

force ..... 

35. Tracing of secondary coil disc'iargi 

36. Tracing of secondary coil discharge 

37. " Make " discharges and " break " discharges of a coil 

38. Handle for electrode . . 

39. Electrodes .... 

40. Tin electrode and sheath 

41. Single current collector 

42. Double collector .... 

43. Commutator .... 

44. Plan of resistance coils .... 

45. Resistance box .... 

46. Adjustable resistance for medical use 

47. Water rheostat . . . . 

48. Graphite rheostat .... 

49. Plan of graphite rheostat 

50. Vertical galvanometer .... 

51. Horizontal galvanometer 

52. Edelmann's galvanometer 

53. Plan of shunt circuit of a galvanometer 

54. Holtz machine ..... 

55. Wimshurst machine 

56. Large Wimshurst machine for medical use . 

57. American Holtz machine, medical type 

58. Front of case of machine, showing connections 

59. Dr. Monell's electrode holder . 

60. Electrodes ..... 

61. Stand electrode .... 

62. Plan of Dr. Morton's method 

63. Arrangement of apparatus for high frequency experiments 

64. D'Arsonval's high frequency apparatus 

65. Lines of current diffusion round an electrode 

66. Blood pressure tracing .... 

67. Blood pressure tracing 

68. Cutaneous electrode .... 

69. Aural electrode .... 

70. Bath plates , . . . . 

71. Bath rest ..... 














Handle for rheumatoid arthritis . 

Paralysis of left trapezius 

Paralysis of the upper part of the right trapezius 

Paralysis of left trapezius. Clavicle seen from behind 

Paralysis of right serratus magnus 

Paralysis of right deltoid 

Paralysis of trapezius, spinati and deltoid on right side 

Electrode for enuresis 

Rectal electrode combined with douche 

Needle electrode for epilation 

Electrolysis of naevus. Proper position of needles 

Electrolysis of naevus. Improper position of needles 

Bipolar fork electrode .... 

Attachment of needles for electrolysis of naevus . 

Eustachian catheter electrode 

Apostoli's uterine electrode and sheath 

Steavenson's electrode for fibre-myoma 

Platinum cautery points 

Schech's handle . . . 

Caiitery handle .... 

Cautery for larger incandescent surface 

Bichromate battery for electric lamps and galvano-cautery 

Accumulator for lamps and cauteries 

Accumulator for lamps and cauteries 

Arrangement ot wires for cautery on continuous current 

Laryngoscope with electric lamp . 
Ophthalmoscope with electric lamp 

Arrangement of lamp in cystoscope 
Cystoscope and dummy . 
Panelectroscope (handle not shown) 
Lamp for abdominal operations 
X ray tube 
Large induction coil 









Page 98, nine lines from end, read Chap, ^.for Chap. VIII. 
Pages 161 and 164, the allusions to an address at 18 Pall Mall 
East no longer hold good. 




Origin of the word Electricity. Dr. Gilbert of Colchester. Early 
medical writers. Remak and Duchenne. Position of electri- 
city in medicine. 

I. Origin of the word electricity = — The founda- 
tion of -the modern science of electricity may be con- 
sidered to have been laid by a medical man, Dr. Gilbert 
of Colchester, Physician in Ordinary to Queen Elizabeth 
^and President of the Royal College of Physicians in the 
'^ year 1600, the date of the publication of his treatise 
De Magnete. 

He extended to a large number of other substances 
the ancient observation that rubbed amber attracted 
light bodies. It seems also that we owe to him the 
word Electricity, for he called all those substances 
Electrics, which when rubbed displayed the same at- 
attractive power for light bodies as amber {r^'Asy.rpov, 
electrum) does, and soon afterwards the word electri- 
city was introduced to indicate this power considered 
as a quantity capable of measurement. 

Dr. Gilbert does not seem to have attempted to apply 
his knowledge of electricity in any way to medicine, 
but he will always be remembered as the pioneer in the 



scientific investigation of electricity and magnetism. 
Dryden has immortalised him in the following lines : — 
" Gilbert shall live till lodestones cease to draw 
And British fleets the boundless ocean awe." 

2. Early medical writers. — It was more than a 
hundred years after Gilbert's time that electricity was 
first brought into use as a curative agent, and in 
the early applications of electricity to medicine the 
statical apparatus was the only form used because it 
was the only one known, but for many years after the 
discoveries of Galvani and Volta statical electricity still 
remained in exclusive possession of the field of electro- 

De Haen (1745) Jallabert (1748) and the Abbe Nollet 
(1749) were the first to apply statical electricity to medi- 

In 1758, Benjamin Franklin relates that in conse- 
quence of the cures reported to have been made in Italy 
and Germany, a number of paralytics were brought to 
him for treatment from various parts of Pennsylvania 
and the neighbouring provinces. 

In 1759 the Rev. John Wesley, the famous divine, 
collected a number of cases in which electricity had 
been tried, and published a treatise entitled The Desi- 
deratum, or Electricity made Plain and Usefid, hy a Lover of 
Mankind and Common Sense. In this are given the details 
of a vast number of cases treated by electricity. Among 
them he mentions that electricity accelerates the pas- 
sage of calculi through the ureters. He also relieved 
tertian and quartan fevers, and hysteria. 

In 1773, Manduyt published a work on statical elec- 

In 1777, Cavallo published in London a complete 
treatise on electricity in theory and practice, with ori- 


ginal experiments. It included general remarks relat- 
ing to Medical Electricity. 

The first records of electrical treatment at a London 
hospital seem to have been in the year 1767, when an 
electrical apparatus was ordered for the Middlesex 
Hospital. And ten years later, in 1777, an electrical 
machine was purchased for the use of the patients in 
St. Bartholomew's Hospital. 

A letter on the subject of medical electricity by Mr. 
John Birch, Surgeon, is to be found in a book called 
An Essay on Electricity, by John Adams. The fifth edi- 
tion of this book was published in 1799, and in it 
Birch's letter occupies fifty pages. He was attached 
to St. Thomas's Hospital, where he had charge of the 
electrical department. 

In England in the earlier half of the present century 
the work of Addison (1837) Golding Bird (1841) and 
Gull (1852) at Guy's Hospital must be noted. Accounts 
of what was done by them may be found in the Guy's 
Hospital Reports for those years, or in Dr. Monell's''' 
book in which they are reproduced in a slightly con- 
densed form. 

Golding Bird also published some lectures on Elec- 
tricity and Galvanism in 1849, and this marks the tran- 
sition period from the dominance of Statical Electricity 
in therapeutics to that of battery and induction coil 
currents. In England since that time little or nothing 
has been done with statical electricity in medicine, 
although M'Clure of Cromer wrote on the subject in 

3. Remak and Duchenne. — Remak in Germany 
and Duchenne in France laid the foundations of the 

* " Manual of Static Electricity in X Ray and Therapeutic Uses." 
S. H. Monell, M.D., New York, 1897. 

B 2 


modern modes of treatment by the battery (galvanism) 
and the induction coil (faradism). Both were eminent 
men ; but the latter especially has left his mark upon 
modern work in medical electricity. It is to Duchenne'-' 
that we owe the principle of applying the currents directly 
to the affected nerves or muscles. Duchenne also showed 
that the muscles could be most easily excited at certain 
points of the surface, which he called points d'ekction. 
These points where shown by R. Remak and von 
Ziemssen to be the places nearest to which the motor 
nerves enter the muscles. They are now called " the 
motor points." (Chap. VII.). 

About 1850 great advances were made in our know- 
ledge of electro-physiology. Du Bois Reymond and 
Pfluger demonstrated the electrical phenomena of living 
nerve and muscle, and established the laws of electro- 
tonus, the phenomena of the contractions of muscle^ 
and the existence of muscle currents. Remak wrote 
upon the catalytic effects of the galvanic current, viz ^ 
upon the use of continuous currents for the relief of 
congestions and chronic inflammatory processes, effects 
which we should now probably speak of as due to an 
action upon the circulation. Our present modes of 
application of electricity in medicine have been built 
upon the investigations of Duchenne, Remak, Brenner, 
von Ziemssen, Boudet de Paris, Onimus, Erb, De 
Watteville, D'Arsonval, and many others of note. 

4. Position of electricity in medicine. — It is now 
one hundred and fifty years since the beginning of 
Medical Electricity. During the whole of that time it 

* " De Telectrisation localisee, et son application a la pathologie 
et a la therapeutique, par courants induits et par courants galvani- 
ques, interrompus et continus." (Translated in an abridged form for 
the New Sydenliam Society by Dr. G. V. Poore). 


has had to fight its way step by step in the face of 
many difficulties, and the most serious of them all has 
been the passive resistance of medical men themselves. 
The vitality which it has shown under adverse circum- 
stances is full of good omen for the future. Medical 
electricity is advancing and will continue to advance 
indefinitely. To those who have followed its develop- 
ments the progress achieved in the past decade is 
enormous. The house to house distribution of electricity 
by Electric Light Companies has called into existence a 
large number of new instruments and methods, and is 
helping to break down the idea that electrical apparatus 
is difficult to keep in order by providing a constant and 
steady supply of current without the need of batteries. 
The introduction of the secondary cell or accumulator 
into general use has also been of great service by afford- 
ing a.' simple means of obtaining electrical currents for 
the use of surgeons. Further, the notion of the treat- 
ment of disease by physical means is becoming a more 
familiar one among medical men, and it is recognised 
that patients often need something more than they can 
obtain from drugs alone. Baths, active exercises, 
passive exercises, massage and shampooing, sunlight 
and exposure to the open air are all called in to-day 
as healing agents. Considerable advances have been 
made lately towards the recognition of the good effects 
of electricity in general therapeutics, as distinguished 
from its use for merely local applications, and it is now 
■clear that the " localised electrisation " of Duchenne 
and of his school covers only a part of the ground 
belonging to medical electricity. 

The discovery of the X rays and the practical apphca- 
tions of them to medicine and surgery which immedi- 
ately followed, have also done good to the cause of 


medical electricity, by bringing electrical apparatus into 
more extended use among professional men, and the 
founding of X ray departments in Hospitals may lead 
to the association with them of proper electro-thera- 
peutic departments, in places where these are not 
already in existence. Most of the London Hospitals 
now have an electrical department more or less effi- 
ciently equipped, and these are of manifest utility. At 
St. Bartholomew's Hospital over six hundred new 
patients are referred yearly to the electrical department 
from all quarters of the hospital. 

There are signs, too, of a revival of statical electricity 
which has been absolutely and totally neglected in 
England since the times of Addison, Golding Bird 
and Gull, with the exception of the work done by Dr. 
M'Clure of Cromer. In France, in the United States, 
and elsewhere, the statical machine has commanded a 
good deal of attention lately, and great progress has 
been made in America in the construction of large 
machines for therapeutic purposes, while the technical 
details of using these instruments have also been care- 
fully studied, with a result that the statical apparatus is 
again taking an important place in electro-therapeutics. 



Fundamental Experiments and Definitions. 

Fundamental Experiments, Hypotheses of Fluids. Electroscopes. 
Conduction. Electric Quantity. Electromotive Force. Poten- 
tial. Electrometers. Electric Density. Capacity. Condensers. 
Leyden Jar. Contact electromotive force. Simple Voltaic cell 
or battery. Oersted's experiment. Magnetic field. Galvano- 
meters. Electromotive force. Resistance. Ohm's Law. 
Practical units. Specific resistance. Measurement of resist- 
ance. Electrolysis. Resistance of an electrolyte. Electro- 
magnetic induction. 

5. Division of the subject. — It is usual for medical 
men to speak of electrical effects as if they were due to 
no less than three distinct kinds of Electricity. These 
we are accustomed to call " Statical Electricity," " the 
Continuous or Galvanic Current" and "the Interrupted 
or Faradic Current." This division, how^ever con- 
venient it may be for purposes of medical treatment, 
has nothing to recommend it when the subject is looked 
at from a scientific point of view. The Science of 
Electricity may best be divided into four branches as 
suggested in Dr. Oliver J. Lodge's " Modern Views of 
Electricity," a book which should be read with care by 
everyone who wishes to have definite and correct 
notions concerning the science. These four divisions 
are : — 

a. Electricity at Rest, or Static Electricity. — This branch 
coincides with that portion of the science generally 
treated of as " Frictional " Electricity. 


h. Electricity in Locomotion, or Current Electricity. — This 
includes the consideration of the continuous current and 
of the interrupted current. 

c. Electricity in Rotation or Magnetism. 

d. Electricity in Vibration or Radiation, a branch of the 
subject treated of in general in that section of Physics 
which deals with the phenomena of Light. 

We only need to consider at all fully the two first of 
these branches, and of these more especially the second. 
In the third branch we shall have to touch slightly upon 
magnetism in order to make clear the nature and 
principles of certain electrical measuring instruments. 

The fourth branch is now coming into the sphere of 
practical utility through the employment of electric 
radiations for the transmission of signals to a distance 
without wires. In the public mind this is associated 
mainly with the name of Signer Marconi, but the dis- 
covery of electric radiation and the first demonstrations 
of the transmission of electric waves to a distance 
without wires, were the work of Professor Hertz. 
Electricity m radiation is also concerned in the phe- 
nomena of the X rays. 

6. Fundamental experiments." — If a piece of 
glass and a piece of resin be taken they neither attract 
each other nor any light bodies to which they may be 
presented. If now they be rubbed together, so long as 
they are not separated, they still display no powers of 
attracting light bodies, but let them be separated and 
they are at once seen to be endowed with the power of 
attracting each other, and each is capable of attracting 
light bodies. They are said to be electrified. If a 

* " On the Mathematical Theory of Electricity in Equilibrium." 
Sir W. Thompson's papers on "Electro-Statics and Magnetism," 
p. 43. Maxwell's " Electricity and Magnetism," vol. i., p. 31. 


second pair of pieces of resin and glass be taken, rubbed 
together and then separated, it may be seen — 

a. That the two pieces of glass repel each other. 

h. That each piece of glass attracts each piece of 

c. That the two pieces of resin repel each other. 

The two pieces of glass are said to be oppositely elec- 
trified to the two pieces of resin, and we can observe as 
a definition that similarly electrified bodies repel each 
other, oppositely electrified bodies attract each other. 
These electrifications are known as vitreous or positive 
and resinous or negative. We also observe that since 
the rubbed glass and resin before being separated 
exhibited no powers of attraction or repulsion on ex- 
ternal bodies the amount of electrification produced on 
the glass exactly neutrahzes the effect of and therefore 
is equal and opposite to that produced on the resin. 

It should here be noticed that an electrified body 
exerts no force on any non-electrified body, but that 
when it appears to do so as in the case in which rubbed 
glass or resin was seen to attract light bodies, the elec- 
trified rubbed substance first acts on the neutral bodies 
and electrically excites them by its influence or "induc- 
tively " {see § ii), so that the attraction shown is not an 
action between an electrified body and neutral matter, 
but between two electrified bodies. 

7. Hypothesis of fluids. — Various hypotheses have 
been put forward to account for this action, all of which 
more or less fail to do so ; two of these may, however, 
be noticed, more especially as, if cautiously used, they 
supply a convenient means for clearly expressing electri- 
cal facts, though it must always be carefully remembered 
that in using these modes of expression we are making 
no assumptions as to the truth or the reverse of the 


hypothesis, but merely using a convenient analogy. 
The first is the " two fluid " theory of Symmer in which 
it is assumed that all matter contains an inexhaustible 
supply of a so-called electric fluid which is capable of 
being split up by friction or otherwise, into equal quan- 
tities of two fluids of opposite properties, viz., the 
so-called vitreous (positive) and resinous (negative) 
electricities, and bodies that display the properties that 
we have said are signs of electrification, are said to be 
charged with a certain quantity of one or other of these 
fluids, a certain quantity of positive or negative elec- 
tricity. This hypothesis gives us in many cases a con- 
venient method of expressing the facts, provided always 
that it be used as such, and is not pushed to the point 
of considering that the electric fluids are any real enti- 
ties or have any actual existence. It is obvious that it 
is an essential part of the hypothesis that both fluids 
shall always be produced in equal quantities. 

In the " one fluid "' theory which was favoured by 
Franklin, bodies that were positively electrified were 
looked upon as containing an excess of electric fluid, 
bodies that w^ere negatively electrified were looked upon 
as suffering from a deficiency, while all bodies in the 
normal neutral state were looked upon as having neither 
an excess nor a deficiency. 

8. Electrics and non-electrics. — All bodies when 
rubbed with suitable precautions are to use Gilbert's 
term, electrics, or rather we should say, that whenever 
any two bodies are rubbed together electrical separation 
occurs, one body becoming positively and the other 
negatively electrified, although in many cases it is diffi- 
cult to observe this owing to the escape of the charge 
by conduction or otherwise, and in fact it is possible to 
arrange all substances in a list, so that when any pair 


of them is rubbed together, the body higher in the Ust 
is positively electrified, while the other is of course 
negatively electrified to an equal extent. 

Such a list is as follows : — Cat's fur, poHshed glass, 
flannel, leather, wood, paper, silk, shellac. Thus : — 
Glass rubbed with cat's fur will be negatively or resin- 
ously electrified, while the same glass rubbed with silk 
will be positively electrified. 

Any instrument by which electrical separation is pro- 
duced may be called an electrical machine. For simple 
experiments, a glass rod which is rubbed with a piece 
of silk on which has been smeared some electrical 
amalgam'-'-' is such a machine. Some more elaborate 
electrical machines will be fully described in a future 

g. Electroscopes. — Before going any further it is 
necessary to consider some means by which we may 
tell when a body is electrified. Instruments for this 
purpose are called electroscopes, or sometimes more 
loosely electrometers. The simplest form of electro- 
scope is that known as the gold leaf electroscope, which 
is made of two strips of gold leaf hung together from 
a wire. When these are electrified they repel each 
other and diverge, and so indicate the presence of elec- 
trification. The instrument is usually enclosed in a 
glass jar which serves as a support and protects the 
gold leaves from disturbances by currents of air. (Fig. i). 
This figure represents the instrument in its simplest 
shape, but many elaborated and improved forms have 
been devised. 

It is easy with this instrument to discern the sign of 
the charge on any electrified body, for if a portion of 

* Electrical amalgam is made of tin one part, zinc two parts, and 
mercury six parts. (Tyndall's " Lessons in Electricity," p. 7). 



the charge be transferred to the electroscope and an 
additional charge be added from a vitreously electrified 
body, e.g., from a glass rod that has been rubbed with 
silk, then if the former charge was negative the leaves 
will collapse, but if positive they will diverge still 

The best way of carrying out this test is as follows : — 
Approach the charged body to be tested to the electro- 
scope. The leaves will diverge. Touch the plate of 

Fig. I. — Stewart's Gold Leaf Electroscope. 

the electroscope with the finger for an instant and they 
will collapse, but on subsequently removing the body to 
be tested, they will again diverge under the effects of a 
charge of opposite sign to that of the body to be tested. 
Now bring up near the electroscope a rubbed glass rod, 
if the leaves collapse the present charge is negative, and 
that of the original charged body was therefore positive. 


The reasons for this procedure will be understood from 
the next paragraph but one. 

10. Conduction. — Let any body, for instance a 
metal sphere, be electrified, taking care that it is sup- 
ported by silk strings or by a glass stem. Let it be 
connected with another similarly supported non-electri- 
fied body by means of a wire for an instant. Now let 
the second body be examined with the electroscope ; it 
will be found to be electrified in the same sense as the 
first body but to a less degree ; the charge of the first 
body has been partly conducted along the wire connec- 
tion and has been divided between the two bodies. If 
connection had been made with a glass rod, a stick of 
resin, or a silk thread, no transfer of charge would have 
occurred. The metal wire is therefore a conductov of 
electricity, the glass rod, &c., are not, they are insulators. 
This e_xperiment explains why it was necessary to sup- 
port the charged bodies we have been dealing with by 
silk threads, it also explains how it was that all the 
electrics known to the ancient electricians were insu- 
lators or non-conductors of electricity, since though 
conductors can be readily excited by rubbing with pro- 
per substances, special means must be taken to insulate 
them that the charge may not leak aw^ay before the 
electrification can be observed. 

Substances vary very much in their power of conduct- 
ing electricity, thus metals are good conductors, water 
and the body are fairly good ones, wood and cotton are 
poor conductors, while wool, silk, oils, resins, dry air, 
and most kinds of glass are good insulators. 

II. Induction. — "A conductor can be electrified 
either by a transfer of electricity between it and another 
conductor, or by an alteration in the distribution of the 
electricity on its surface, without any transfer of electri- 


city between it and another conductor. In the former 
case the body is said to be electrified hy conductions in 
the latter hy induction or inductively. 

Take a hollow metal vessel, insulate it by hanging it 
up by silk threads, and connect it with an electroscope." 

If the vessel be unelectrified and we introduce into it 
an electrified body, taking care not to touch the sides of 
the vessel so that no charge passes from the electrified 
body to the vessel, the electroscope will indicate a 
charge, and on being tested it is found to be a charge of 
the same sign as that on the charged body introduced 
into the vessel, e.g., if the charged body is a piece of 
rubbed glass, the electroscope will indicate positive 
electricity. If now it be removed without having 
touched the interior of the vessel, the leaves of the 
electroscope will collapse, and the vessel will be left 
without charge, if, however, it has been allowed to 
touch the vessel, the leaves will remain divergent, but 
the body will be found to be completely discharged. 

In the first case the vessel is said to be electrified by 
induction, and from the second case we see that the 
observed induced electrification is exactly equal to, and 
is of the same sign as that of the inducing body. Had 
we momentarily connected the vessel to earth so as to 
discharge the first induced electrification, and then 
removed the charged body without touching the vessel, 
the vessel would be found to be charged with the oppo- 
site kind of electricity to as great an extent as in the 
first case. Similar effects are produced whenever an 
electrified body is brought near any other body, and 
this is what was referred to in § 6, when it was stated 
that the light bodies apparently attracted by an electri- 
* Faraday's " Experimental Researches on Static Electrical Induc- 
tive Action." Maxwell's " Electricity and Magnetism," vol. i., p. 32. 


fied glass rod, &c., were first electrified by its influence. 
In the language of the two fluid theory an electric 
charge in any body reacts on the neutral fluid in the 
bodies near it, attracting towards itself an equal quantity 
of the fluid of opposite sign and setting free an equal 
quantity of the fluid of similar sign to itself. This is 
generally illustrated diagrammatically by considering 
the side of the body nearest to the glass rod as charged 
with — electricity and the opposite side charged with + 
electricity, the attraction thus overbalancing the repul- 

"Acting inductively on an uncharged conductor pro- 
duces no charge on it as a whole, but merely induces 
equal and opposite charges on its two sides or ends."* 

12. Electric quantity. — Hitherto in this chapter 
the consideration of quantity of electricity has been left 
in the background, and electrification has been spoken 
of rather as a state or quality super-induced in bodies 
by certain processes. It is now necessary to arrive at 
a definite conception of this state as a measurable 
quantity, i.e., as brought about by the presence of a real 
or hypothetical something which can be measured and 
which is called electricity, a something which has been 
referred to for convenience sake in the language of the 
■^' fluid" hypothesis as if it were an actual fluid, but 
which, it must be borne in mind, is not that, whatever 
■else it may be. Let us suppose the existence of a 
something which is measurable and which when present 
in any body endows it with the properties just described 
under the name of electrification, and which is called 
Electricity. This electricity then is of two kinds, one 
named positive or vitreous, and one negative or resinous. 
It has been seen already that positive electricity repels 
* Ayrton, " Practical Electricity," p. 97. 


positive, and that negative repels negative, while posi- 
tive electricity attracts negative and vice versa. This 
has to be expressed in terms of some unit, to be chosen 
once for all. 

Unit of Quantity.-'' — That quantity of electricity, which 
when supposed collected at a point will repel an equal 
quantity of similiar electricity collected at a point, and 
placed at unit distance from the first, v/ith unit force 
shall be taken as the unit quantity of electricity. 

Now in this definition the unit quantity of electricity 
is made to depend on the units of length and of force, 
and this latter is defined with reference to the units of 
length, mass and time. Hence the unit quantity of 
electricity has been completely defined in terms of the 
units of length, mass and time. For scientific purposes 
these are taken as one centimetre, one gramme and one 
second respectively. 

There is one matter that has not explicitly been taken 
into consideration in thus defining the unit quantity of 
electricity, viz., the medium in which the action betw^een 
the two charges takes place. It is assumed, however, 
that this is air, or more strictly speaking, a vacuum. 

Now the attraction or repulsion between two quanti- 
ties of electricity is proportional to each, i.e., is propor- 
tional to the product of the two quantities. It is also 
inversely proportional to the square of the distance be- 
tween them, always of course supposing that the two 
quantities are collected at two points. 

13. Electromotive force, potential. f — " What- 
ever produces or tends to produce a transfer of electrifi- 
cation is called electromotive force. Thus when two 

* Maxwell's " Electricity and Magnetism," vol. i., p. 44. 
t Quoted from Maxwell's "Elementary Treatise on Electricity,'^ 


electrified conductors are connected by a wire, and 
when electrification is transferred along the wire from 
one to the other, the tendency to this transfer, which 
existed before the introduction of the wire, and which 
when the wire is introduced, produces this transfer, is 
called the electromotive force from the one body to the 
other along the path marked out by the wire. 

" To define completely the electromotive force from 
one point to another, it is necessary in general to specify 
a particular path from the one point to the other along 
which the electromotive force is to be reckoned. In 
many cases, e.g., in electrolytic, thermo-electric and 
electro-magnetic phenomena, the electromotive force 
from one point to another may be different along dif- 
ferent paths ; if we restrict our attention, however, as 
we must do in this part of our subject, to the theory of 
the equilibrium of electricity at rest, we shall find that 
the electromotive force from one point to another is the 
same for all paths drawn in air from the one point to 
the other. 

"The electromotive force from any point along a path 
drawn in air, to a certain point chosen as a point of 
reference, is called the electric potential at that point. 

" Since electrical phenomena depend only on differ- 
ences of potential, it is of no consequence what point of 
reference we assume for the zero of potential, provided 
that we do not change it during the same series of 

" In mathematical treatises, the point of reference is 
taken at an infinite distance from the electrified system 
under consideration. The advantage of this is that the 
mathematical expression for the potential due to a small 
electrified body is thus reduced to its simplest form. 

" In experimental work it is more convenient to 



assume as a point of reference some object in metallic 
connection with the earth, such as any part of the 
system of metal pipes conveying the gas or water of a 

"It is often convenient to assume that the walls, floor 
and ceiling of the room in which the experiments are 
carried on have conducting power sufficient to reduce 
the whole outer surface of the room to the same poten- 
tial. This potential may then be taken for zero. When 
an instrument is enclosed in a metallic case the potential 
of the case may be assumed to be zero. 

" If the potentials at different points of an uniform 
conductor are different there wall be an electric current 
from the places of high to the places of low potential. 
At present we are dealing with cases of electric equili- 
brium in which there are no currents. Hence in the 
cases with which we have now to do the potential at 
every point of the conductor must be the same. This 
potential is called the potential of the conductor. 

14. Physical analogies. — " The idea of electrical 
potential may be illustrated by comparing it with pres- 
sure in the theory of fluids and temperature in the 
theory of heat. If two vessels containing fluids are put 
into communication by means of a pipe, fluid will flow 
from the vessel in which the pressure is greater into 
that in which it is less till the pressure is equalised. 
This, however, will not necessarily be the case if one 
vessel is higher than the other, for gravity has a ten- 
dency to make the fluid pass from the higher to the 
lower vessel. Similarly when two electrified bodies are 
put into electric communication by means of a wire, 
electrification will be transferred from the body of 
higher potential to the body of lower potential. Again 
if two bodies at different temperatures are placed in 


thermal communication, either by actual contact or by 
radiation, heat will be transferred from the body at the 
higher temperature to the body at the lower tempera- 
ture, till the temperature of the two bodies becomes 
equalised. The analogy between temperature and 
potential must not be assumed to extend to all parts 
of the phenomena of heat and electricity. We must 
also remember that temperature corresponds to a real 
physical state, whereas potential is a mere mathemati- 
cal quantity the value of which depends on the point of 
reference we may choose. To raise a body to a high 
temperature may melt or volatilize it, to raise a body, 
together with the vessel which surrounds it, to a high 
electrical potential produces no physical effect whatever 
on the body. Hence the only part of the phenomena 
of electricity and heat, which we may regard as ana- 
logous, is the condition of the transfer of heat or of 
electricity according as the temperature or the poten- 
tial is higher in one body or in the other. With respect 
to the other analogy — that between potential and fluid 
pressure — we must remember that the only respect in 
which electricity resembles a fluid is that it is capable 
of flowing along conductors as a fluid flows in a pipe." 

In terms of this analogy the electricity is compared 
to the fluid, while the pressure of the fluid at any point 
answers to the potential of the electricity at a corre- 
sponding point, the difference of pressure between two 
points causes the flow of fluid from one to the other, 
while similarly the electromotive force or difference of 
potential between two points causes the flow of elec- 
tricity from one to the other. 

The conception of electric potential is a very difficult 
one, and this is not the proper place for a discussion of 
it in all its bearings ; enough has been said in the long 

c 2 


quotation from Clerk Maxwell to give some idea of the 
meaning of the word, but the student who wishes to 
obtain a thorough insight into it cannot do better than 
read Clerk Maxwell's Elementary Treatise on Electricity^ 
giving special attention to Chapter III., on " Electrical 
Work and Energy." In most of what follows, and es- 
pecially in the part which refers to electricity in motion,, 
the idea of electric pressure in connection with the word 
potential will be the dominant one ; but it must always 
be remembered that this idea of pressure is based on 
the analogy of the electric flow to a fluid flow, and this 
is at best very imperfect. 

15. Electrometers.— The only thing that can be 
observed in connection with electricity at rest is a 
difference of potential. It is possible to measure the 
quantity of electricity driven through certain instru- 
ments, just in the way that a quantity of water driven, 
through a water meter can be measured, and some of 
these instruments Avill be discussed in a future chapter ; 
but for the present we can only appreciate electrical 
charge by observing a difl'erence of potential, and elec- 
troscopes and electrometers are instruments for showing 
or measuring difl'erences of potential. 

The gold leaf electroscope has been shortly referred 
to above. The divergence of the leaves of this' instru- 
ment may be taken as an indication that the knob or 
disc, or way by which electricity enters the instrument,, 
is at a different potential to the walls of the room, or to 
that of the metal cage that surrounds some forms of the 
instrument, but obviously without further observation it 
does not tell whether the potential is higher or lower, 
i.e., more positive or more negative, and further tests 
must be made to discover this. Neither does it give 
us more than the roughest indication of the amount of 


difference of potential. In cases where there is a great 
difference of potential, and a delicate gold leaf electro- 
scope is likely to be spoilt, rougher forms may be used, 
£.g., Dutch metal or even pith balls suspended by linen 
threads may be used instead of the more delicate gold 

If it is required to measure a difference of potential 
an electrometer must be used. There are many forms of 
these, most of which are due to the inventive genius of 
Lord Kelvin. Descriptions of the various forms will 
be found in most text-books, such as for instance in 
S. P. Thompson's Lessons in Electricity and Magnetism, or 
the article "Electrometer" in the last edition of the 
Encyclopedia Britannica ; but best of all in Sir W. 
Thomson's papers on Electrostatics and Magnetism, 
pp. 263, et seq. 

16. Distribution of charge^ Density.— It has 
been observed that the whole of an electric charge 
resides on the surface of a charged conductor, and this 
has been proved by direct experiment in many ways. 
It is found that while the distribution over a sphere is 
uniform, as might be expected from the symmetry of 
the figure, it is not so on conductors of other shapes. 
On these the charge per unit of surface, which is called 
the density, is greater the greater the curvature of the 
surface till at a sharp edge or a point the density 
becomes so great that at high potentials a discharge 
takes place. For this reason if a point is attached to 
a highly charged conductor a stream of charged par- 
ticles of air is repelled from the point giving rise to a 
wind setting from the point and rapidly discharging the 

17. Action of points. — This action of points be- 
comes of great importance in some electrical machines, 


and in some kinds of electrical treatment. In the first 
place the presence of a point on a charged conductor 
renders it difficult to keep a charge on the conductor, 
however well it may be insulated. But the same effect 
will occur if a point be presented to a charged con- 
ductor ; for the charge, which we will suppose is posi- 
tive, of the conductor acting inductively on the point 
will induce a negative charge at the point, the density 
of which will become so great that it will be discharged 
to the original conductor, neutralising its positive 
charge, and leaving the conductor which bears the 
point positively charged if it is insulated. It is by this 
means that the prime conductors of most electrical 
machines are charged from the excited plate or other 
moveable part. 

i8. Capacity. — The quantity of electricity that is 
required to raise the potential of any conductor from 
zero to unity, all other conductors in the neighbourhood 
being kept at zero potential, is called its Capacity. 

As the charge resides only on the surface of a charged 
body, the capacity of a conductor is determined by the 
extent of its surface, and a body of a large surface has a 
larger capacity than a body of smaller surface. 

When a conductor is said to have a given capacity, 
it must not be thought that the conductor can hold only 
a certain fixed charge, in the way in which a bottle can 
be said to hold only so much water, because the quan- 
tity of electricity that can be put into a conductor of a 
certain capacity depends upon the potential or pressure 
at which it is charged. A body of unit capacity holds 
unit quantity when charged to unit potential, and holds 
ten times as much when charged to ten times the 
potential. On this account it is necessary to know 
both the capacity of a conductor, and the potential to 


which it has been charged, before forming any idea 
of the quantity of electricity which it contains. The 
capacity of a conductor may be compared to the capa- 
city of an elastic bag. The amount of air or of water 
that can be forced into an elastic bag depends upon the 
pressure at which it is forced in, and provided the bag 
does not burst, it can be made to hold more and more 
by increasing the pressure at which it is charged. 

The capacity of a conductor is increased by bringing 
near to it other conducting bodies, which are maintained 
at zero potential by being connected to earth, and it 
may be stated generally that the nearer the " earthed " 
conducting bodies are to a conductor the greater be- 
comes the capacity of that conductor. 

The importance of this point is well brought out by 
an example. The capacity of a sphere of ten centi- 
metres radius suspended freely in space is ten units, 
but if another sphere of eleven centimetres radius be 
placed concentrically to it, so that the two spheres are 
separated one from another all round by one centimetre 
of air, and if the outer sphere be maintained at zero 
potential by connection to earth, then the capacity of 
the inner sphere is no longer ten, but no units, while if 
the radius of the outer sphere be reduced to ten and a 
half centimetres, the capacity of the inner one would 
become 210 units.''' 

19. Condensers. f An apparatus consisting of two 
insulated conductors, each presenting a large surface to 
the other, with a small distance between them, is called 
a condenser, because when one conductor is connected 

* If fl be the inner and b the outer sphere, then the capacity of a 

is given by the formula r^^ — 

t Maxwell's Elementary Treatise 011 Electricity, Chap. VIII. 



to earth, a small electromotive force is able to charge 
the other with a much larger quantity of electricity 
than if it stood alone, i.e., its capacity is increased by 
the proximity of the other conductor. 

The simplest form of condenser consists of two metal- 
lic discs supported on insulating stems and facing each 
other, the intervening non-conductor or dielectric being 
air. If now a different dielectric, as for example, a 
sheet of glass, be inserted instead of air, the capacity of 
the condenser will be found to be different and greater 
than before, thus the action across the dielectric de- 
pends on the nature of the dielectric. 

Fig. 2. — Leyden jar. 

Since a glass condenser has a higher capacity than an 
air condenser, glass is said to transmit induction better 
than air, or in other words, glass has a higher dielectric 
constant or specific inductive capacity than air. 

20. Leyden jar. — The electrical condenser most 
often used in experiments on static electricity is that 
known as the Leyden jar (fig. 2). 

The ordinary form of this apparatus is a glass jar or 
bottle coated inside and out with metal foil to within 
two or three inches of the top. Through the cork of 


the bottle a wire passes, terminating above in a knob, 
and below in a chain to make metallic contact with the 
inner coating. To charge the jar the outer coating is 
connected to earth, and so kept at zero potential, while 
the inner coating is connected with the conductor of an 
electrical machine. The charge given to the inner 
coating acts inductively upon the outer coating across 
the dielectric of the jar, which is thus able to retain its 
charge. It may be discharged by bringing a metaUic 
conductor, which is in connection with the outer coat- 
ing, near to the knob of the jar. A spark will occur and 
the jar is discharged. 

The capacity of a Leyden jar depends upon the area 
of the surfaces coated with tinfoil, and also from what 
has been said in § i8, upon the thinness of the glass ot 
which it is made. If the glass be very thin it may give 
way under the strain when charged to a high potential, 
and be broken to pieces. 

21. Contact electromotive force. — It was observed 
at the end of the last century by Volta, that when dis- 
similar metals, such as zinc and copper, were brought 
into contact in air, electrical separation took place, and 
a small difference of potential was set up between the 
metals, the zinc being positive to the copper, or at 
a higher potential. Under these circumstances this 
difference of potential does not efface itself by dis- 
charging across the junction of the two metals, as a 
difference of potential between two parts of a homo- 
geneous conductor would do, because the electromotive 
force set up at the junction of the two metals could only 
discharge itself across the junction by a flow in the 
opposite direction to that in which it tends to cause a 
flow, but that is absurd. But if the two pieces of metal 
while in contact are immersed in some liquid that is 


capable of acting chemically on one of them, e.g.^ dilute 
sulphuric acid, a complete "circuit" is formed, and the 
discharge can take place through the liquid, which 
undergoes decomposition thereby, and the difference of 
potential being continually renewed at the expense of 
the chemical energy caused by the action of the liquid 
upon the zinc plate, a continuous discharge takes place 
round the circuit in the following w^ay : — 

Positive electricity passes across the junction of cop- 
per and zinc, and then from the zinc across the liquid 
to the copper again. If the connection of copper to zinc 
be by a wire, as is usually the case, we may use the 
language of the two-fluid hypothesis and look on the 
junction as a sort of pump driving positive electricity 
round the circuit, so that it passes from zinc across the 
liquid or electrolyte to copper and back to the zinc 
again along the metallic connection between it and the 
copper, thus making a true circuit. 

22. Voltaic cell. — Such an arrangement is called a 
voltaic cell, and but for disturbances that will be more 
fully considered in Chap. III., it would give a con- 
tinuous current, till either the zinc or the exciting 
liquid (called the electrolyte) was exhausted. The dif- 
ference of potential in a cell, or its electromotive force, is 
due to the contact electromotive force of the metals 
forming the poles of the cell, though in certain cases 
this may be slightly modified by the liquid used. It is 
possible to increase the electromotive force by joining 
together a sufficient number of simple voltaic cells, 
zinc of one to copper of the next. Such a combination 
of cells is called a battery, and the cells are said to be 
joined in series; and the electromotive force of the 
battery is equal to the sum of the electromotive forces 
of the cells which compose it. 


It is customary in some textbooks to speak of the 
zinc plate of a battery as the positive plate, and the 
copper or other plate as negative, while the terminal 
attached to the zinc plate is called the negative pole, 
and that attached to the copper the positive. The 
origin of this very confusing nomenclature is no doubt 
the fact that in the battery the positive direction of flow 
of the current is from zinc to copper, and that zinc is 
said to be electro-positive to copper. But in the con- 
necting wire the positive direction of flow of the current 
is from copper to zinc (see fig. 3), and as this is the 

Fig. 3. — Single voltaic cell showing poles and direction of flow inside and 
out of cell. 

portion of the circuit that we are most concerned with, 
the word positive will be used to denote the positive 
po]e of the battery and also the plate connected with it, 
when it is necessary to specify this. This is in con- 
formity with the usage of electrical engineers, who 
speak of the peroxide plates in an accumulator as 
" positives." 

23. The magnetic needle. — When a magnet is 
suspended freely at the surface of the earth it is found 
that it swings so as to set itself with one pole pointing 
towards the North (or at least approximately so) and 


the other towards the South. The poles are spoken of 
as the North seeking and South seeking poles respectively, 
and their names are abbreviated into N. and S. for 

24. Oersted^s experiment. — Let a small magnet, 
say a compass needle, be suspended freely at rest. It 
will point North and South, now over it let there be 
carried a wire joining the two terminals of a Voltaic cell 
or battery in such a way that its course from copper to 
zinc along the w^ire shall be from South to North, 
i.e., so that the current (the positive direction of flow) 
is from South to North, then the North seeking end of 
the magnet will be deflected towards the West. This 
observation is due to Oersted of Copenhagen, and it 
w^as formulated by him into a law for telling the direc- 
tion of flow in a circuit, thus : — Imagine a man swim- 
ming with the current in the wire, i.e., from copper to 
zinc and facing the needle, the North seeking end of the 
magnet will always be deflected towards his left hand, 
whatever the position of the wire with regard to the 
magnetic needle. 

25. Magnetic field. Lines of force. — The 
region of space about any magnet and throughout 
which we consider its action is called its fields and 
lines of magnetic induction or lines of force round a 
magnet can be mapped out. These will then all start 
from points or surfaces indued with N magnetism and 
end in points or surfaces indued with S magnetism, and 
the intensity of a magnetic field at any point will be 
given by the number of lines of force which cross per 
unit of surface at right angles to them at that point. 

It is easy to map the field of force round any magnet, 
since every magnet tends to set itself parallel to the 
lines of force at the point where it is. If then the mag- 


net whose field is to be mapped be laid down on a sheet 
of white paper, and a small compass needle be moved 
about in its vicinity, the direction of the needle at any 
point w411 give the direction of the lines of force at that 
point and these can be plotted on the paper. And soft 
iron filings, in a magnetic field, become magnets them- 
selves by induction, and so set themselves along the 
lines of force, mapping them out to the eye in a very 
beautiful manner. 

If a sheet of paper be laid down over a bar magnet, 
and iron filings be sifted over the paper, and the paper 
be gently tapped, they will arrange themselves into a 
figure composed of curved lines which emerge from one 
pole, and pass round to converge at the other (see 
fig- 4)- 

S "~n] ,- 

Fig. 4. — Lines of force of a bar magnet. 

26. Field of force about a wire carrying a 
current. — To return to the electric current. We can 
now draw a deduction from Oersted's experiment (§ 24), 
viz., that there must be a magnetic field of force about 
every wire that is carrying a current, and since, when 
we are facing the magnet and swimming with the cur- 
rent, the N pole is always deflected to the left whatever 


the position of the magnet with regard to the wire, it 
follows that the lines of force must pass round the wire 
in circles, and it is easily shown that they do so by 
scattering iron filings on a card, through a hole in which 
a vertical wire carrying a moderately strong current is 
passed ; when the card is tapped the filings instantly 
arrange themselves so as to map out the lines of force 
as circles round the wire ; also if we look along the wire 
from copper to zinc, i.e., with the current, the direction 
of the lines, the direction in which a N pole will move, 
is that of the hands of a clock. If a wire be bent into 
the arc of a circle, when a current passes through this 
arc there will be a field of force at the centre of the 
circle due to the current at all points of the arc. If the 
arc were in the plane of the paper and the current ran 
counter clock-wise in it, the direction of the lines of 
force would be vertically up from the paper. 

27. Galvanometers. — Oersted's discovery enables 
us to make an instrument for measuring the current in 
any circuit. Such an instrument is called a. galvanometer; 
or when, as is frequently the case, it is used merely to 
indicate the presence of a current it may be called a 

In its simplest form, stripped of all non-essentials, the 
galvanometer consists of a coil of one or more turns of 
wire with a small magnet suspended freely at the centre. 
The coils may be, and generally are, circular, but fre- 
quently for convenience of construction or other reasons 
they are wound in other shapes. The needle being 
suspended freely sets itself parallel to the magnetic field 
that happens to exist at the place where the galvano- 
meter is to be used, and the coils of the instrument are 
then set parallel to the needle and therefore to the 
magnetic field at the place. Hence the field due to a 


current circulating in the coils will be at right angles to 
the permanent field with which it is to be compared and 
will tend to deflect the needle. 

In order to read the deflections of the needle when 
the galvanometer is in use, one of several devices may 
be applied. The simplest, where very accurate reading 
is not essential, is to attach to the needle a light pointer 
which passes over a scale. 

By multiplying the number of turns of wire in the 
galvanometer coils the action of the current on the 
needle becomes increased in proportion, each turn 
exercising its own effect. On this account the name of 
*' multiplier " was once given to the galvanometer. But 
it must not be forgotten that if the number of windings 
be largely increased, an obstacle to the passage of the 
current, or a resistance is thus introduced, which may 
have the efl"ect of largely diminishing the current flow- 
ing through the coils. It is therefore necessary to wind 
galvanometer coils so as to suit the special purposes for 
which they are intended to be used. The galvanometers 
used for medical purposes are generally wound with 
several hundreds or even thousands of turns. The 
resistance thus added to the circuit may be consider- 
able, but as the resistance of the body is itself very high, 
the eflect of the galvanometer resistance in diminishing 
the current is comparatively slight, and is quiet unim- 
portant as compared with the advantage gained by the 
multiplying effect of the turns of wire upon the needle. 
Thus the small currents used in medical treatment are 
enabled to produce large deflections of the galvano- 
meter needle. 

It must not be forgotten that the deflection of the 
needle of a galvanometer is not in any way a direct 
measure of the current circulating in it. Galvanometers 


are constructed to suit the purposes for which they are 
intended, and whilst some instruments will give con- 
siderable deflections with minute or even infinitesimal 
currents, others may require currents of comparatively 
huge magnitude to produce even a slight movement of 
the needle. On this account it is necessary, before 
comparing the deflections of one galvanometer with 
another, to be able to express their deflections in cur- 
rent, and galvanometers may be graduated by compar- 
ing them with standard instruments or by the use of a 
voltameter (see Chap. V.). In buying an instrument, 
however, it is customary to specify the magnitudes of 
current which it is proposed to measure with the 
galvanometer required ; the instrument maker is then 
able to provide a suitable instrument, which has been 
already graduated to read directly into current. 

There are certains features which from the nature of 
the work they are called upon to perform are common 
to most galvanometers for medical purposes. The most 
important is perhaps the method of graduation. These 
galvanometers are invariably of the fixed coil or " tan- 
gent " form, that is to say, the current indicated by any 
reading, is proportional not to the angle of deflection^ 
but to the trigonometrical tangent of that angle. Hence 
it is necessary that the circle on which the position of 
the needle of the galvanometer is read must be gradu- 
ated, not uniformly, but so that the readings are angles 
whose tangents increase uniformly. 

28. Electromotive force. Resistance. — A cur- 
rent is set up in a conductor by electromotive force 
(see def., § 13), that is to say, the current in any part 
of a circuit is due to the difference of potential between 
the ends of that portion of the circuit. This can be 
measured by means of a suitable electrometer. It is 


soon found in working with currents that with different 
amounts of wire in the circuit different currents are 
produced by the same electromotive force. There is 
therefore another factor that determines the magnitude 
of the current besides the electromotive force, and this 
factor is called the resistance of the circuit. 

29. Resistance of conductors.— The resistance of 
a conductor is the inverse of its conductivity, and the 
conducting qualities of a body may quite well be ex- 
pressed in terms of its resistance ; thus the same idea 
is conveyed by saying that copper has a high conduc- 
tivity and that it has a low resistance. As a rule it is 
more customary and more convenient to speak of the 
resistances of bodies rather than of their conduc- 

The resistance of a body depends upon the material 
of which it is made (see "Specific Resistance" below), 
and upon its length and its thickness. Thus a thick 
wire has a lower resistance than a thin wire of the 
same length and material, and a short wire has a lower 
resistance than a long wire of the same thickness and 

30. Specific resistance. — The electrical resistance 
of any material is a property peculiar to that material 
just as its hardness or colour or density is. Most metals 
are good conductors but they vary greatly among them- 
selves in their electrical conductivity. Silver is the 
best conductor of electricity and copper comes near to 
it. Platinum has about six times the resistance of 
silver, and iron has a resistance slightly greater than 
that of platinum. As a general rule alloys have a 
higher resistance than the pure metals ; German silver 
having about fourteen times the resistance of copper. 
Tables showing the relative conductivity of metals, and 



other bodies, are given in textbooks such as S. P. 
Thompson's Lessons. 

Tables of resistance are also made with the specific 
resistances of the materials tabulated. Such tables will 
be found in Everett's Units and Physical Constants or in 
S. Lupton's Numerical Tables. 

The specific resistance of a material is defined as the 
resistance of one cubic centimetre of the substance con- 

If the specific resistance of a substance is known, the 
resistance of any wire or rod of that substance can be 

The resistance is directly proportional to the length 
of the conductor, and inversely so to its cross-section. 

In general the resistance of metals increases with 
temperature. That of carbon, however, decreases con- 
siderably, and in this respect behaves in the same way 
as electrolytic conductors do (see heloiv). The carbon 
filament of an incandescent lamp has nearly twice the 
resistance cold that it possesses when hot. 

31. Ohm^s Law. — The law showing the relation 
between electromotive force, resistance and current was 
enunciated by Dr. G. S. Ohm and is known as Ohm's 
law. It is as follows : — The strength of the current in any 
circuit or part of a circuit varies directly as the electromotive 
force in that circuit and inversely as the resistance of the circuit. 
This may be expressed in symbols thus : — 

c = | 

Where C stands for the current, E for the electromotive 
force, and R for the resistance. From this formula we 

obtain in addition E = CR, or R ^^ . Thus we can 

calculate either C, E, or R if the values of the other 
two symbols are known. 


32. Measurement of resistance. — Ohm's law 
may be applied to measure the resistance of any given 
conductor, or rather to compare the resistances of two 

Suppose that the current, passing through the galvano- 
meter can be read off from the deflection of the needle, 
and it is required to find the value of the resistance R. 
Join up the resistance R with the galvanometer and 
battery as in the figure, then since by Ohm's law 

Fig. 5. — Typical circuit. 

if E the electromotive force of the battery is known, and 
C, the value of the current, is read off from the galvano- 
meter, then the total resistance of the circuit can be 
easily calculated. But this is made up of R the re- 
sistance to be measured, and v the resistance of the 
battery, and ^ that of the galvanometer. E.g., suppose 
a Daniell's battery of electromotive force i'o8 volts and 
resistance -58 ohm, and a galvanometer whose resist- 
ance is 66-3 ohms are used, and the reading of the 
galvanometer is '006 ampere (six milliamperes) we get 

R + r + p- = = 180 ohms, 


(7/ R = 180 — 66*88 = ii3"i2 ohms. 

D 2 


When exact measurements are required, however, we 
should not rely on knowing the electromotive force or 
resistance of the battery with sufficient accuracy for 
this, so the method must be so modified as to eliminate 
these. Methods of doing this are described in Practical 
Physics by Glazebrook and Shaw, in the Textbooks of 
Science series, or in Practical Physics, vol. ii., by Balfour 
Stewart and Gee. The method, however, is quite good 
enough to be useful in certain cases. 

By obvious modifications this method may be used 
for the determination and comparison of the resistances 
of batteries or galvanometers, or for the determination 
of the electromotive force of a battery. 

33. Practical units. — The electro-magnetic units, 
as in the case of the electrostatic units, are all ulti- 
mately defined in terms of the units of mass, length, 
and time, and as in all electrical and other scientific 
calculations these are taken to be one gramme, one 
centimetre and one second respectively, the system of 
units is known as the absolute or centimetre-gramme- 
second (C.G.S.) system. It is found, how^ever, that for 
practical calculation and use these units are not of a 
convenient size, e.g., the units of electromotive force 
and of resistance are inconveniently small, and that of 
current is inconveniently large. The following system 
of units derived from these has therefore been adopted 
for practical use. 

Electromotive force. — The practical unit is called the 
Volt. It is a little less than the electromotive force of 
one Daniell's cell (see § 51). 

Resistance. — The practical unit of resistance is called 
an Ohm. The Paris Congress of Electricians in 1884 
defined an unit of resistance to be called a " legal Ohm.'' 
It is represented by the resistance of a column of pure 


mercury at o° C, of an uniform cross- section of one 
square millimetre, io6 centimetres long, and weighing 
14-4521 grammes, it is slightly less than the true ohm.'*' 

Current. — The current which is given by an electro- 
motive force of one volt acting through a resistance of 
one ohm is called one Ampere. 

Quantity. — One ampere flowing for one second carries 
one Conlomh of electricity past any point in the circuit. 
Another unit of quantity much used by engineers is the 
quantity of electricity which would be carried by one 
ampere in an hour. This is called an anipeve-liouv. It 
is equal to 3600 coulombs. 

Capacity {see ^1^). — That capacity which would re- 
quire one coulomb to charge it to one volt, is called one 

Even these units are inconveniently great or small at 
times, so" certain prefixes are used to the names to 
denote multiples or sub-multiples of these quantities. 
Thus, a megohm is one million ohms, a microvolt is one- 
millionth of a volt, a microfarad one-millionth of a farad, 
a milliampere is one-thousandth of an ampere ; this last 
is the unit of current used in medicine. 

34. Current sheets— current density. — When a 
current is led into a large conductor the lines of flow 
spread out through the conductor. They all of course 
pass from the anode to the kathode, but spread out into 
sheets in doing so. The current which passes across 
unit of sectional area, taken at right angles to the lines 
of flow at any point, may be called the density of the 
current at that point. In the case of a current in a 
wire conductor we consider the whole current since 

* One thousand million CG.S. units. 

t These names commemorate the labours of Volta, of G. S. Ohm, 
of Andre Ampere, of Coulomb, and of Michael Faraday. 


the whole sectional area of the wire is taken into ac- 
count, but with currents flowing in large and hetero- 
geneous conductors like the human body, or even in 
electrolytes where the density of the current may vary 
from point to point, it is necessary in order to estimate 
the effect at any point, to take into consideration the 
density at that point rather than the whole current. 
For the physiological effects are largely dependent on 
the density, that is the ratio of current to sectional 

35. Electrolysis. — In § 22 it w^as pointed out that 
during the passage of an electric current through a 
battery the liquid, or as we then called it the electro- 
lyte, was decomposed, and this decomposition is essen- 
tial to the passage of the current. Examining into the 
decomposition more closely, it may be looked on as if 
it took place as follows : — Owing to the difference of 
potential set up between the plates, say of zinc and 
copper, the zinc plate being positive attracts to itself 
the electronegative portion or ion of the electrolyte. 
In the case of sulphuric acid (H.2SO4) this is the group 
of atoms SO4. At the same time the copper plate being 
at the lower potential, and therefore negatively charged 
with regard to the zinc, attracts the electropositive ion, 
i.e., the hydrogen and the state of affairs may be thus 
represented : — 

+ — + — + — + — + — 
i.e., a chain of molecules polarized under the influence 
of the contact difference of potential between copper 
and zinc. But the ion SO4 is capable of combining with 
the zinc and so neutrahzing its positive charge, and the 
ion H2 is set free on the copper, thus neutralising the 
corresponding negative charge there. Immediately of 


course the same action recurs owing to the continuously 
acting contact electromotive force between copper and 
zinc. In this way a continuous current is kept up, 
and a continual double procession of the molecules of 
the electrolyte or ions occurs in the liquid part of the 
circuit, the electropositive ion passing always towards 
the copper or positive pole of the battery and the elec- 
tronegative ion towards the zinc, so that we may 
regard the copper plate as receiving positive electricity 
continually from the electrolyte, and passing it on to 
the circuit. The hydrogen given off at the copper plate 
does not escape instantaneously, and unless means are 
taken for removing it, it will set up a back or reverse 
electromotive force which will greatly reduce the effi- 
cient electromotive force of the battery. The battery is 
then said to be polarized. Many methods, chemical and 
mechanical, have been suggested for overcoming this 
difficulty, some of which will be described in Chap. III. 

If the wires leading from the terminals of a battery 
are not joined but are led into another electrolyte, an 
action corresponding to that which takes place in the 
battery will occur. There will be a tendency to de- 
compose the electrolyte, and if there is sufficient elec- 
tromotive force in the circuit to overcome the reverse 
electromotive force of the electrolyte, electro-decompo- 
sition or electrolysis will take place. Taking the case of 
water (in practice the water is slightly acidified with 
sulphuric acid to increase its conductivity) the changes 
are as follows : — 

36. Anode and kathode. — Suppose that the poles 
of the battery are connected to two platinum plates in 
the water. These plates are called the electrodes. 
That connected wath the copper pole is the one by 
which the current (considered as a flow of positive 


electricity) enters the electrolyte and is called the Anode, 
that connected with the zinc is called the Kathode, i.e., 
the pole by which the current leaves the solution. In 
the beginning the anode is positive, the kathode nega- 
tive. The ions in the case of water are hydrogen and 
oxygen and the former is electropositive and therefore 
appears at the kathode or negative pole and is called 
the kation, while the oxygen appears at the anode and 
is called the anion. The arrangement of the molecules 
may be represented thus : — 

Kathode H.3 O Ho O H, O Anode. 
_ 4- — + — +— + 

If the electromotive force of the battery is not suf- 
ficient to overcome the back electromotive force due to 
the chemical affinity of the oxygen and hydrogen for 
each other, matters will rest like this, the electrolytic 
cell is polarized,''' the current is stopped, and no appre- 
ciable decomposition or electrolysis will take place, but 
if the electromotive force is sufficient, i.e., about two 
volts or more, decomposition will proceed, hydrogen 
being given off at the kathode, and oxygen at the 

37. Laws of electrolysis. — The laws of electrolysis 
were discovered by Faraday ;f they are as follows : — 

a. The amount of chemical action is equal at all parts of a 
circuit. E.g., if several electrolytic cells, or voltametersl 
as they are often called, be arranged in a circuit, the 

* It is easy to show that there is an actual reverse electromotive 
force in the electrolytic cell, by suddenly cutting out the battery and 
completing the circuit in w^hich the electrolytic cell is included 
through a galvanometer, which will then indicate a small current in 
the opposite direction. 

t "Experimental Researches," Series V. and VII. 

+ For an account of Voltameters, see Chapter V. 


amount of decomposition will be the same in each. If 
they are water voltameters the same amount of hydro- 
gen will be given off in each, if the electrolyte is copper 
sulphate solution the same amount of copper will be 
deposited in each. The same applies in the case of 
the anions. If some of the voltameters contain water 
and others contain sulphate of copper solution, the 
quantities of hydrogen and copper respectively will be 
proportional to their chemical equivalents. 

h. The amount of any ion liberated in any given time is pro- 
portional to the strength of the current, and to the chemical 
equivalent of the ion. 

The chemical equivalent for hydrogen is unity, there- 
fore the weight of hydrogen liberated by one ampere 
running for one second, i.e., by one coulomb of electri- 
city, is the electro-chemical equivalent of hydrogen. For 
any other ion the product of the weight liberated by 
one coulomb, multiplied by the chemical equivalent of 
the ion, is called the electro-chemical equivalent of that 
ion. The electro-chemical equivalent of silver is very 
nearly -ooiiiS grammes per coulomb, and the quantity 
of silver which one ampere would deposit in an hour is 
4-0246 grammes. 

38. Resistance of an electrolyte. — Just in the 
same way as the resistance of a metal or other solid 
conductor is considered, we may speak of the resistance 
of a liquid or electrolyte. There is more difficulty in 
measuring this in practice in consequence of the reverse 
electromotive force of polarization, but if alternate cur- 
rents be used the specific resistance of an electrolyte 
may be found, uncomplicated by polarisation effects. 
The fact that electrolysis is taking place in an electro- 
lyte does not prevent the consideration of its resistance 
in the same way as that of a non-electrolyte. The 


specific resistance of water is high, and the purer the 
water the higher it becomes ; it would appear, accord- 
ing to the latest experiments, that absolutely pure water 
if it could be obtained would be a perfect non-conductor. 
Compared with metals the resistances of solutions are 
high, thus a salt solution has a specific resistance up- 
wards of four million times greater than that of copper. 

39. Heating effects of a current. — A voltaic cell 
may be regarded as an apparatus by means of which the 
energy of the chemical action between the zinc and the 
electrolyte (§ 22) can be in part converted into electrical 
energy and the process may be spoken of as a combus- 
tion in which the fuel is the zinc. If a piece of zinc be 
simply dissolved in sulphuric acid in a test tube the 
energy liberated is wasted and serves only to warm the 
contents of the tube, but when the zinc is arranged in a 
voltaic cell some of the energy can be utilised in the 
form of an electrical current flowing through the circuit, 
and this current can be made to do work, or can be 
again converted into heat in any part of the external 
circuit of the cell. When an electrical current flows 
through a circuit its energy is absorbed by the resistance 
of the circuit and is dissipated in the form of heat, or in 
other words a wire carrying a current becomes heated 
by the passage of the current through it. The amount 
of heat generated depends (i) upon the resistance of the 
wire, being proportional to the resistance, and (2) upon 
the magnitude of the current, being proportional to the 
square of current. Accordingly when it is wished to 
avoid the production of heat and the consequent loss of 
energy in a circuit, the conductors should be of low 
resistance (§ 29) ; and conversely when the current is to 
be used for the production of heat, as in the wire loop of 
a galvano-cautery instrument, or in the filament of an 


incandescent lamp, then the resistance of the part of the 
circuit which is to be heated must be made as high as 
may be necessary for the circumstances of the case and a 
comparatively bad conductor must be chosen for that 

The energy expended in a conductor may be calcu- 
lated from the current in the conductor and the electro- 
motive force acting upon it, the figure obtained by 
multiplying the E.M.F. (in volts) by the current (in 
amperes) giving the rate of the expenditure of energy in 
terms of an unit known as a watt. 

If E represents the electromotive force and C the 
current, then the watts W expended in the conductor 
are expressed by EC. 

In any simple conductor the energy expended takes 
the form of heat. We are consequently able to calcu- 
late the rate at which heat is generated in the con- 
ductor ; and if we know its specific heat and the rate at 
which it loses heat at its surface, we can calculate the 
the temperature after the current has passed for any 
given time. 

A watt is not a measure of work done, but of the 
rate of doing work. To obtain a measure of work done 
the time during which it goes on must be also con- 
sidered. Thus one watt for one hour, or shortly, one 
watt-hour is a measure of work done. 

By Ohm's law E = RC, and if in the equation W = EC 
RC be substituted for E, we obtain the formula 
W = C^R, for the rate of doing work, for losses in a con- 
ductor, or for the heating effects of a current traversing 
a conductor. 

The Board of Trade unit in which the energy sold to 
consumers by the Electric Light Companies is measured 
is one thousand watt-hours, and costs about sixpence. 


This amount of energy can be made up in various 
ways ; for example, taking the ordinary pressure of 
supply as loo volts, ten amperes at that pressure for 
one hour, or one ampere for ten hours, alike represent 
the amount of energy of one unit. An ordinary incan- 
descent lamp of sixteen candle power requires about 
sixty watts to keep it at a proper degree of brightness, 
and on the circuit of loo volts it takes a current of -6 of 
an ampere. Five of these lamps would use 300 watts, 
and if kept going for five hours the amount of energy 
absorbed would be fifteen hundred watt-hours, or one 
Board of Trade unit and a half, costing ninepence, if 
the price of the unit were sixpence. 

40. Electro-magnetic induction. — When two dis- 
tinct circuits are near to each other, currents in one will 
^'induce" currents or, more correctly, electromotive 
forces in the other. 

The induced currents are of momentary duration, and 
appear only when the inducing current is made to vary, 
as for example, when it is turned on or turned off. The 
current induced at the starting of the inducing current 
is opposite in direction to the inducing current, and the 
current induced at the break of the inducing current 
has the same direction as the inducing current. These 
induced currents were discovered by Faraday, and on 
that account the induced currents employed in medicine 
are still known as " Faradic currents " among medical 

In § 26 it was stated that there is a magnetic field of 
force about every wire carrying a current, and the 
effects of electro-magnetic induction just referred to, 
depend upon the field of force surrounding the wire of 
the inducing circuit, and generally it may be said that 
every change of the magnetic condition of the space 


round a conducting circuit produces an induced E.M.F. 
or current in the circuit. Thus the increase or decrease 
of a current in the inducing circuit, or the approach or 
withdrawal of the inducing circuit will change the mag- 
netic conditions round the other circuit which may be 
termed the "secondary" circuit, and will set up a cur- 
rent in it. Also for the same reason the approach or 
withdrawal of a magnetic pole will set up a current 
in the secondary circuit during the periods of approach 
or withdrawal, and since the induced current depends 
upon the variation of the magnetic field in which the 
secondary circuit is placed, it matters nothing whether 
the field is caused to vary by moving a magnet or by 
making and unmaking a magnet by any means, or by 
varying a current in the neighbouring circuit. 

The production of electric currents by electro-magnetic 
induction is of enormous practical importance. The 
commercial developments of electricity rest entirely 
upon the dynamo-machine, which is purely an appa- 
ratus for the generation of electricity by the induction 
effects of magnetic fields upon moving coils of wire. 
The importance of the dynamo-machine lies in the fact 
that it affords a means for the direct conversion of 
mechanical power into electrical power. It does this 
so simply, so cheaply, and so efficiently, that the pri- 
mary battery is becoming obsolete as a source of elec- 
trical energy, and survives to day only for a few special - 
purposes, or in remote places. 

41. Induced electromotive force. — It was stated 
at the commencement of § 40, that "currents in one 
circuit will induce currents, or more correctly, electro- 
motive forces " in another. The meaning of the cor- 
rection is that although the induction of currents implies 
the induction of electromotive forces, yet electromotive 


forces may exist without being able to give rise to 
currents. It follows from sections 13 and 21 that an 
•electromotive force can only give rise to a current when 
there is a conducting path for the current. In the case 
of a circuit acting inductively upon a conductor near it, 
the latter would be the seat of a current if it formed 
part of a closed conducting circuit ; but if it did not 
do so it would be the seat of an electromotive force 
only, as its circumstances would be against the pro- 
duction of a current in it. 

In order to arrive at the magnitude of induced cur- 
rents we must consider that by Ohm's law (§ 31) this 
depends upon two quantities, the electromotive force 
and the resistance of the wire. This latter is constant, 
since it depends only on the wire ; the electromotive 
force alone varies. Its direction has been already con- 
sidered, its magnitude is determined by the following 
law : — The total induced electromotive force in any 
■closed circuit is proportional to the rate of change of the 
number of magnetic lines of force through the space 
enclosed by the circuit. But the number of lines of 
force, or in other words, the strength of the magnetic 
£eld produced by a current in a circuit is proportional 
to the current in that circuit. Hence the law may run 
" the induced electromotive force in any closed secondary circuit 
is proportional to the rate of change of current in the primary 

42. Self-induction.— When a current is sent through 
a circuit, the magnetic field which is set up round the 
conductor reacts upon the conductor itself, just as we 
have seen it do upon a neighbouring circuit, and thus 
at the moment of completing a circuit the rise of cur- 
rent in it to its proper value is retarded by an induced 
electromotive force of opposite sign in the wire itself ; 


while when the circuit is broken there is a momentary 
reinforcement of the current by an induced electro- 
motive force of the same sign as that existing in the 
wire. This action of an increasing or decreasing cur- 
rent upon its own circuit is spoken of as an action of 
self-induction, and the reinforcement of the current at 
the break produced in this way can be amplified and 
made use of as will be seen later in the account of medi- 
cal induction coils (Chap. V.). 




Essentials of a good battery. Electromotive force ot cells. Capa- 
city of cells. Polarization. The Smee, Bichromate, Danielle 
Grove and Bunsen batteries. Leclanche battery. Dry batteries. 
Chloride of silver battery. Oxide of copper battery. Sulphate 
of mercury battery. Stohrer's battery. Accumulators. Table 
of batteries. Choice of a battery. Care of a battery. 

43. Essentials of a good battery. — Numerous 
modifications of Volta's original cell have been from 
time to time proposed with the object of improving it^ 
so as to obtain as high an electromotive force as pos- 
sible, to diminish the internal resistance, and to secure 
constancy of action. For medical work the most im- 
portant point of all is to find a cell which will remain 
for a long time in good order without attention, and in 
which no wasteful chemical action goes on when the 
battery is not in use. On this account the Leclanche 
battery (§ 53) or some modification of it has been almost 
universally adopted as the cell par excellence for medical 

44. Electromotive force of cells = — The limit of 
electromotive force that can be obtained from a single 
cell is soon reached, since, as shown in § 21, it depends 
almost entirely on the contact electromotive force be- 
tween dissimilar substances. Tables are found in elec- 
trical textbooks of metals arranged in order, the most 
electro-positive at the head of the table, the most electro- 


negative at the foot. An abbreviation of such a table" 
is the following : — 












This order is given for the elements in contact in 
presence of dilute acid ; under other circumstances the 
order is liable to some alteration. 

It follows that the battery with the greatest electro- 
motive force would be one, the poles of which consisted 
of the two materials at the extreme ends of the table, 
and most of the improvements in batteries made with 
the object of increasing the electromotive force have 
been by substituting metals further down the list for 
the copper plate of Volta's cell. Thus in Smee's cell we 
find a platinized silver plate is used for the positive pole, 
in Grove's battery a platinum plate, while in Bunsen's 
carbon is used. Until, therefore, it becomes practicable 
to use magnesium or sodium instead of zinc, we can 
hardly expect to obtain primary batteries of higher 
electromotive force than those in which zinc and carbon 
poles are used. The best of these batteries, when work- 
ing properly, have an electromotive force of something 
under two volts. That of a Bunsen's cell is from 1*8 to 
I '9 volts. 

■ * Miller's " Chemistry." 



As will be seen in the description of secondary bat- 
teries a positive plate of peroxide of lead affords a 
means of getting a high electromotive force, and the 
combination of it with a zinc negative plate has been 
suggested under the name of the zinc-lithanode bat- 
tery, and it is said to have an electromotive force of 
2-5 volts per cell. 

If several cells be coupled together in series, that is 
to say, with the negative pole of the first joined to the 
positive pole of the second, and so on, the electromotive 
force of the combination measured from the positive 
pole of the first to the negative of the last cell, will be 
equal to the sum of the electromotive forces of the cells 
taken separately, thus, when high electromotive forces 
are required, the arrangement of a sufficient number of 
cells in series provides a means of obtaining it. If ten 
cells of an electromotive force of i'5 volts apiece be 
arranged in series the electromotive force of the whole 
battery will be fifteen volts. In medical treatment an 
electromotive- force of 30 or 40 volts is commonly re- 
quired ; and a medical battery is therefore provided 
with a suitable number of cells connected together in 
series to give such a voltage. 

45. Internal resistance. — This is determined by the 
nature of the fluid in the cell, by the distance between 
the plates, and by the area of the plates. The internal 
resistance is low if the plates be large and close to- 
gether, and high if the plates be far apart or small. If 
the whole circuit of a cell be considered, and divided 
into two parts, the external circuit in the wire, and the 
internal inside the cell itself, then a comparison of the 
resistances of the two parts will show what proportion 
of the total electrical energy of the battery is available 
for use in the external circuit, and what proportion is 


expended uselessly inside the cell itself; for example, in 
the case of a cell having an electromotive force of 1-5 
volts, with an internal resistance of three ohms, and 
connected through an external resistance of six ohms, 
the energy expended in the outside circuit will be two- 
thirds, and that expended inside the cell will be one- 
third of the total. Of the total difference of potential, 
one-third (or '5 volt) will be used up in the cell, and the 
remaining two-thirds (or i volt) will represent the avail- 
able electromotive force of the cell for doing work in the 
outside circuit. 

If the external resistance be 997 ohms and the 
electromotive force and internal resistance be as be- 
fore, then the available electromotive force acting upon 
the external circuit will be very nearly the same as the 
full voltage of the cell ; actually it will be -997 of 1-5 

Thus one sees that in certain cases the internal re- 
sistance of a cell is an important factor in determining 
its value as a source of current, while in other cases it 
is insignificant. In working with the large resistances 
of the human body the internal resistance of the cells 
composing the battery is an unimportant matter, as it 
forms a small fraction of the total resistance of the cir- 
cuit, and the loss of electromotive force inside the cells 
is therefore a small fraction also. 

In working with low external resistances, as in cau- 
tery work, and to a less degree in the illumination of 
parts of the body by incandescent lamps, the internal 
resistance of the cells becomes important, and special 
forms of cell with low internal resistances are designed 
for such work. 

46. Arrangement of cells. — The arrangement of 
cells in series has already been alluded to ; and is re- 

E 2 


presented in figure 6. Cells may also be arranged in 
parallel (fig. 7), that is to say two or more cells may 
have their positive poles connected together to form one 
pole of the battery, and their negative poles in like 
manner to form the negative pole. When cells are 
connected in series the electromotive force of the battery 
is the sum of the electromotive forces of the cells com- 
posing it ; the internal resistance of the battery is also 
the sum of the internal resistances of the cells. When 
similar cells are connected in parallel the electromoti^^ 
force of the combination is no more than the electro- 
motive force of one of its components ; but its internal 

Fig. 6.— Six cells arranged in series. 

Fig. 7. — Six cells arranged in parallel. 

resistance is diminished in proportion to the number 
of cells coupled together. With six cells in parallel the 
internal resistance is one-sixth of that of one cell. It is 
sometimes useful to couple up the cells which are at 
hand in the best manner for obtaining the desired result, 
as the following example will show : — 

Suppose the resistance of a cautery is -i ohm, and the 
cells to hand are ten bichromate cells of 1-6 volts each 
and "5 ohm internal resistance, and suppose that the 
cautery requires eight amperes to heat it. If the cells 
are coupled up in series we shall indeed get an electro- 
motive force of sixteen volts acting through a resistance 
of 5-1 ohms, and this will give a current of 3 amperes, 


but if they are coupled in parallel, the battery resistance 
will be only -05 ohm, and the total resistance will be but 
•15 ohm in the whole circuit. True the electromotive 
force will be only i-6 volts, but by Ohm's law the cur- 
rent in this case will be io-6 amperes. In the former 
case the cautery would not be heated, in the latter we 
should have enough current and to spare. Vice versa, it 
is futile to arrange batteries in parallel when a current 
has to be passed through a high resistance, such as 
the human body, a resistance of at least 1000 ohms, 
compared with which the internal resistance of thirty 
Leclanche cells in series is small. 

47. Polarization. — Much attention and ingenuity 
have been concentrated upon securing constancy of 
current and absence of polarization in batteries. This 
is easily seen to be an important matter, for nearly all 
batteries "undergo a rapid fall of electromotive force 
when any large current is taken from them. Thus, for 
example, a form of cell recently put upon the market 
had an electromotive force of i'5o8 volts on open cir- 
cuit, but after being short circuited through a wire of 
low resistance for fifteen minutes the electromotive force 
had fallen to -433 volts. Polarization of a cell is mostly 
caused by alterations in the surfaces of the plates of the 
cell, and chiefly by the condensation of hydrogen on the 
inactive plate which sets up a reverse electromotive 
force, and so reduces the available electromotive force 
of the cell, at the same time reducing the available 
area of the plates, and thereby increasing the internal 
resistance of the cell (see § 45). 

There are other causes which tend to produce a fall- 
ing off in the current that a cell can give, particularly 
the exhaustion of the exciting fluid, if it be not renewed 
from time to time. 


To prevent polarization it is necessary to take some 
measures that will check or disperse the accumulation 
of hydrogen on the positive pole. 

48. Depolarizers. — Depolarizing methods can be 
conveniently grouped under three heads: — (a). Me- 
chanical methods, (b). Liquid depolarizers, (c). Solid 

In Smee's battery the surface of the silver plate is 
roughened by being platinized, i.e., covered with finely 
divided platinum, the effect of which is that the bubbles 
of hydrogen are able to form and escape more easily. 
In Walker's modification of this battery (see § 58, 
Stohrer's battery), the rough surface of the carbon plate 
used plays the same part, but it probably acts chemi- 
cally also by causing oxidation of the hydrogen in the 
same way that the carbon of charcoal filters causes 
the oxidation of the organic matter of impure water. 
Another mechanical method of hindering polarization 
is to keep the exciting fluid well stirred by forcing air 
through it or otherwise. None of these methods, how- 
ever, are so efficacious as the use of chemical means, 
that is to say the use of some oxidising agent in the cell 
whereby the hydrogen is consumed, instead of being 
deposited on the positive plate. The simplest method 
of doing this is to add to the exciting liquid some 
powerful agent that will oxidise the hydrogen as fast 
as it is liberated. Thus chromic acid is used in the 
"bichromate" battery (§50) invented by Poggendorf. 
The chemical action of the depolarizer upon the hydro- 
gen reinforces the electromotive force of the couple. 
Another liquid depolarizer that is much used is strong 
nitric acid, but as this attacks zinc violently it is neces- 
sary to separate it from the zinc plate by the use of a 
semi-permeable porous partition or porous pot, and the 



battery then becomes a two-fluid battery. In figure 8 
the arrangement of a two-fluid battery is shown ; V is 
the porous pot containing one Uquid and one plate, the 
other Hquid and the other plate standing outside it. 

There are several solid depolarizers in use, the one 
best known being peroxide of manganese, which is used 
in the Leclanche cell, and in several of the " dry " cells. 
Oxide of copper is also used. Fused chloride of silver 
is the depolarizer in a battery known as the chloride 
of silver cell. 

=_^=:3aa ei±fi ir.Fci= ; 

Fig. 8.— Two-fluid cell. 

49. Smee^s battery. — This battery is of interest, as 
representing the simplest advance on the copper-zinc 
couple of Volta ; it was invented in 1840. In its usual 
form it is made of two flat plates of zinc, separated 
from one another above by a block of wood which 
supports a platinised silver plate between the zincs. 
The exciting liquid is dilute sulphuric acid i to 10. In 
spite of ^the roughened surface of the silver plate the 
battery soon polarizes, and its available electromotive 
force is not much more than -5 volt. 


50. Bichromate battery. — This is a favourite form 
of cell where large currents are required occasionally. 
Its constancy, however, is by no means perfect. Its 
plates are of zinc and carbon, and the exciting liquid 
consists of a solution of potassium bichromate and sul- 
phuric acid. A part of the sulphuric acid sets free 
chromic acid, and this being a very powerful oxidising 
agent, combines w4th the hydrogen liberated on the 
carbon plate by the action of the battery, and is reduced 
to chromous oxide ; this combines with a further quan- 
tity of sulphuric acid to form chromous sulphate, which 
remains in solution, giving the liquid a dark green 
colour. After a time, crystals of chrome alum (potas- 
sium chromium sulphate) will be deposited, which are 
hard and difficult to dissolve. Sodium bichromate has 
been strongly recommended instead of the potassium 
salt, as the sodium chrome alum is very much more 
soluble ; the sodium salt also contains, weight for 
weight, more chromic acid than the potassium salt. A 
suitable formula for preparing the exciting liquid is the 
following : — Potassium bichromate or sodium bichro- 
mate, 6^ ounces ; water, 35 ounces ; sulphuric acid, 
6 ounces. 

When the battery begins to show signs of being 
exhausted an additional ounce of acid per quart may 
be added. 

The zincs of this battery must always be removed 
from solution immediately after use, and in fact should 
be well washed and frequently re-amalgamated, if the 
battery is to give the best effect. Bichromate cells are 
frequently fitted up in portable induction coil sets. 
Forms of bichromate battery are also known to medical 
men under the name of Stohrer's and Reiniger's 
batteries ; but they are not to be recommended, as 



they require much attention and cleaning. Stohrer's 
battery will be more fully described in § 58. The out- 
ward form of the bichromate battery varies very much. 
A very familiar shape is that of a bottle (fig. 9). The 
plates are suspended from a vulcanite lid carrying bind- 
ing screws, and the zinc plate can be drawn up out of 
the liquid into the neck of the bottle when the battery 
is not in use. 

Fig. 9. — Bichromate battery. 

51. DanielPs battery. — The oldest and most con- 
stant form of two-fluid battery is that known as 
Daniell's cell. So constant is this cell that it has been 
proposed and frequently used as a standard of electro- 
motive force. For rough purposes we may take the 
electromotive force of a Daniell's cell at one volt. A 
Daniell's cell consists of a copper plate placed in a 
solution of sulphate of copper, which is kept saturated 
by having a few crystals of copper sulphate on a shelf 


near the top of the hquid ; separated by a porous par 
tition is a zinc plate in solution of sulphate of zinc 
slightly acidified with sulphuric acid. Frequently the 
copper plate is made also to serve as the containing 
vessel. The porous partition while it prevents the 
mixing of the two solutions, offers but little resistance 
to the electrolytic passage of the current. The reactions 
then are as follows : — Zinc is dissolved at the zinc plate 
and hydrogen would be set free at the division between 
the two liquids but for the presence of the copper sul- 
phate solution which being itself an electrolyte is de- 
composed into sulphuric acid, which passes inwards 
from the porous partition, and copper which is de- 
posited at the positive pole. Since this latter is already 
of copper there is no tendency to polarization here at 
all, and any falling off in the electromotive force of 
the cell is due to bad amalgamation or some other 
fault at the zinc plate. Daniell's batteries, are some- 
times arranged as " gravitation batteries," the porous 
division being abohshed and the lighter liquid with the 
zinc plate standing above the heavier sulphate of copper 
solution. Daniell's cells might be useful in medical 
practice for charging accumulators. 

52. Crroves^ and Bunsen^s batteries. — These have 
for their depolarizer strong nitric acid. In the former 
the positive pole is a platinum plate, in the latter a 
plate or rod of hard gas carbon. In both batteries the 
positive pole is contained in a porous pot filled with 
strong nitric acid, and this is surrounded by the zinc 
plate contained in a vessel filled with dilute sulphuric 
acid (fig. 8). The fumes and the corrosiveness of nitric 
acid form the greatest objection to the use of this bat- 
tery. It must be taken to pieces and cleaned every time 
it is used. If it can be set up in a draught cupboard or 



outhouse it is useful for recharging accumulator cells, 
but the process is troublesome. 

53. The Leclanche battery. — The cell most uni- 
versally used for medical work is the Leclanche battery 
(fig. 10), the exciting solution in which is a saturated 
solution of ammonium chloride (sal ammoniac). The 
negative pole is a zinc rod and the positive pole a carbon 
plate or rod. This is surrounded by the depolariser, 
manganese dioxide, which is able slowly to oxidise any 

Fig. 10. — Leclanche cell. 

hydrogen evolved by the action of the cell. In the older 
forms of Leclanche cell the carbon pole was packed 
tightly in a porous pot with fragments of carbon and 
granular manganese dioxide. Another form of cell has 
no porous pot, and thus its internal resistance is some- 
what reduced, and the carbon has attached to it a con- 
glomerate formed of manganese dioxide and carbon 
pressed into blocks. This form is called the agglo- 
merate type. 


When the circuit is open there should be practically 
no action between the solution and the zinc ; but when 
the circuit is closed the zinc is dissolved, forming a 
double chloride of ammonium and zinc, and an oxy- 
chloride of zinc, while ammonia and hydrogen are 
evolved at the carbon pole. If only a small current 
is taken from these cells their action is fairly constant, 
but if much current is used the oxidising action of the 
manganese dioxide is unable to keep pace with the 
evolution of hydrogen and the cell becomes polarized, 
though it recovers completely if left for some hours 
on open circuit. The electromotive force of a new 
Leclanche cell is about 1-5 volts. The advantages of 
the battery are that it possesses great powers of re- 
covery, has no appreciable local action and may conse- 
quently be left for months at a time without attention, 
and has a fairly high electromotive force. Against 
these we must set the fact that its electromotive force 
runs down rapidly when it is called on to produce a 
current of any magnitude. 

None of the cells in w^hich dilute acid is used for the 
exciting liquid can be left to themselves in the way that 
Leclanche batteries can, for in all of them the local 
action would soon destroy the zinc if it were not re- 
moved from the acid as soon as the battery was done 
with, and on that account alone acid cells are not 
suitable for medical purposes, since they require too 
much attention. Medical batteries must allow of be- 
ing carried to patients' houses when necessary, and 
cells with acid liquids in them are most awkward ; 
accordingly, except for special purposes, the Leclanche 
cell is almost universally employed, for in it the zinc 
can be left always in position without waste from local 
action, and the cell can be closed in with pitch or 


cement, to prevent any escape of fluid from within ; 
these conveniences are purchased at the cost of a high 
internal resistance and of a tendency to polarization, 
but for most medical work these objections are not very 
serious, because the amount of current required in most 
cases is only a few thousandths of an ampere (5 to 50 
milhamperes). Even w^hen the portability of the bat- 
tery is not important the Leclanche element is still pre- 
ferred, for once installed in a cellar or a cupboard, it 
can be left alone without attention for years, and if 
large cells can be used instead of small ones, the internal 
resistance can be reduced, while the capacity of the cell 
for doing work can be increased. The Leclanche cell 
then is the one most commonly used for medical pur- 
poses, and its management, mode of action, defects and 
good qualities should all be mastered by those who 
intend to work at the subject of medical electricity. 

Numberless modifications of this cell have been put 
upon the market at different times, but these have dif- 
fered from the original type, mainly in such details of 
construction as shape of cell, omission of porous pot, 
and shape of plates. We shall further consider one of 
the modifications in treating of " dry " batteries (§ 54). 

To preserve Leclanche cells in good order they must 
receive a little attention from time to time about once 
in six months or so. The larger sizes in glass jars can 
be easily inspected, and the condition of the zincs and 
the level of the liquid ascertained. 

If the zincs are blackened they should be scraped and 
amalgamated, and the liquid can be renewed by add- 
ing solution of sal ammoniac to replace any loss from 
evaporation. The cells must not be filled to more than 
two-thirds of their capacity. If the amount of work 
done by the battery has been large and the solution has 


become milky, it had better be withdrawn by means of 
a syringe or a syphon, and fresh solution put into its 
place. The proportion of six ounces of sal ammoniac 
to a pint of water makes a solution of proper strength. 
The upper inch of the glass cells ought to be brushed 
over with vaseline or hot paraffin w^ax to prevent creeping 
of the salts. This is the formation of crusts of the sal 
ammoniac around the top of the cell, it is harmful be- 
cause it may lead to corrosion of connecting wires, so 
breaking the circuit. 

When hard crystals form in masses at the bottom of 
the cell and round the zincs it is time to take down the 
battery and to set it up afresh. These crystals are a 
double chloride of zinc and ammonium, and are in- 
soluble in water. When they have formed in the outer 
vessel, they have probably formed in the porous pot as 
well, and their presence there is not desirable, because 
they increase the internal resistance of the cell and 
block up the interstices of the carbon and manganese 
dioxide. If there is reason to think that the cells are 
worn out, the porous pots may be recharged with man- 
ganese dioxide and broken carbon, which can be bought 
ready mixed, or better still they can be replaced by 
new ones. The management of the small Leclanche 
cells used in portable batteries is much more difficult,, 
because it is impossible to see their condition ; one can 
do little beyond emptying out the liquid with a fine 
syringe and putting in fresh sal ammoniac solution in 
the same way from time to time, and to do even so 
much as this is a tiresome operation. If the cells when 
new are charged with pure zinc chloride, i in 6, instead 
of with sal ammoniac, they will last a long time without 
the formation of the hard crystals, and can be recharged 
with fresh zinc chloride solution, slightly acidified witli 



hydrochloric acid. Unfortunately, however, these small 
cells as sent from the makers, have already inside them 
a charge of sal ammoniac, requiring only the addition of 
water to set them in action. It is of no use to charge 
these with the zinc chloride. The most expensive part 
of the small medical Leclanche cell is its vulcanite case. 
In the dry cell this is dispensed with and the latter are 
therefore cheaper. 

54. Dry batteries. — These are in many ways ex- 
ceedingly convenient. They are sealed cells of the 

Fig. II. — Hellesen's dry cell. 

Leclanchd type. They will work in any position and 
require no special attention whatever, but it must be 
remembered that all sealed forms of cell have a capacity 
for work strictly limited by the original charge of 
chemicals, and cannot be restored to action when run 
down by the addition of fresh exciting liquid. In most 
of them the zinc plate is shaped like a canister and 
forms the containing vessel of the cell, it is packed with 
a paste of exciting material, and inside this is the 


carbon and manganese dioxide. Cells of this type can 
be obtained from the General Electric Co. (the E. C. C. 
cell), and from Messrs. Siemens Bros, (the Obach cell 
and the Hellesen cell). 

The " Hellesen's patent dry cell " works very satis- 
factorily (fig. 11). Like the other dry cells it is a modi- 
fied Leclanche battery as the poles consist of zinc and 
carbon and the exciting salt is sal ammoniac mixed 
with quicklime, while the depolarizer is manganese 
dioxide. They are made in several sizes, the smallest 
■size for portable medical batteries, weighs only eight 
ounces, and is a very good cell. It will last for a year 
and a half or two years with proper care, and after that 
time must be rejected. They cost eighteenpence apiece. 
The larger sizes are very good for working induction 
coils. A newer cell by the same firm known as Obach's 
dry cell is also recommended as a good dry cell. 

5^. Chloride of silver cell. — The chloride of silver 
battery was invented in 1868 by Warren de la Rue and 
Hugo Miiller, and modified and improved by Skrivanoff 
in 1883. It possesses some good qualities, but it is a 
rather expensive cell to buy. Unfortunately the silver 
chloride passes into solution after a time, and is reduced 
to metallic silver on the surface of the zinc. Local 
action then sets in, and the cell rapidly deteriorates. 
An American firm claims to have overcome these diffi- 
culties and now manufacture a very neat and convenient 
form of this cell. 

56. Lalande oxide of copper cell. — This cell as 
modified by Edison consists of plates of zinc and 
copper ; oxide of copper compressed upon the copper 
plate acts as a depolarizer, caustic soda is the exciting 
fluid. The cells are said to be very constant, and can 
furnish large currents. There is little or no local 


action. Their electromotive force is low, '8 of a volt, 
and they are not suitable for a portable battery (fig. 12), 
but might have a use in remote places for cautery 
work or for charging accumulators. They can be had 
from the General Electric Co. in several sizes. 

57. The sulphate of mercury battery. — A bat- 
tery that has been used for medical purposes, especially 
in the pocket induction coils sold by M. Gaiffe, of Paris, 
consists of plates of zinc and carbon in a solution of 

Fig. 12. — Edison-i^alande cell. 

sulphate of mercury. In the apparatus mentioned 
above two small cells are generally supplied in the form 
of little ebonite trays with carbon plates on which is 
placed a small quantity of the commercial sulphate of 
mercury, and a little water ; the zinc plates are then 
laid on this and are kept from contact with the carbon 
by three vulcanite studs. The electromotive force is 
about 1-45 volts per cell. 

Latimer Clark's standard cell is a form of sulphate of 




mercury cell, which is used in laboratory experiments, 
but it requires the utmost delicacy in management, and 
is used solely as a standard for the comparison of elec- 
tromotive forces ; its electromotive force is i'434 volts 
at 15° C. 

^S. Stohrer^s battery. — This battery, once largely 
used in medical work, is a modified form of bichromate 

Fig. 13.— Stohrer's battery. 

battery. The elements, zinc and carbon, are arranged 
in a double row on a wooden bar, so that a double row 
of glass or earthenware cells containing the exciting 
fluid can be raised up to them in such a manner that 
the correct pairs of plates dip into each cell (see fig. 13). 
The battery may be made up to contain 20, 30, 40, or 
even 60 cells, these form a double row in a strong oak 


box, and a beam of wood with a deep channel cut in it 
extends from end to end of the box in the middle line ; 
the pairs of plates are all suspended from this beam by 
stout brass rods, which convey the current from the 
cells to a travelling collector. 

The collector which slides in the groove of the beam 
carries two flat brass springs which make connection 
with the brass rods from which the pairs of plates hang. 
From the springs the current is led through a com- 
mutator to a pair of binding screws, and from these the 
wires may be led to the place where the current is 
required. It may be noticed that Stohrer's battery was 
originally designed for use with dilute acid only, as in 
Walker's modification of Smee's cell, but the addition 
of the chromic acid depolarizer obviously improves its 

The battery is not portable owing to the quantity of 
corrosive liquid in the cells, and it is very troublesome 
and difficult to keep it clean, and its zinc plates amalga- 
mated. It is therefore becoming obsolete. 

59. — Accumulators or secondary batteries. — A 
so-called secondary lattery has the property that when it 
is run down and exhausted it may be renewed by 
driving an electric current into it and thus setting up an 
electrolysis that brings the plates and the electrolyte 
back to their former state, while in the primary batteries 
it is necessary to renew these. There is no more 
actual storage of electricity in these batteries than in a 
primary battery. Either may be looked upon as a store 
of energy, and in both the energy stored is energy of 
chemical action. Secondary batteries are classified 
into two types, in both of which the plates are of lead. 
The older cell of the Plante type has porous lead plates, 
placed in dilute sulphuric acid as the electrolyte ; these 

F 2 



cells then require "forming," that is, a current is passed 
through them for a certain time, and they are then 
allowed to discharge themselves through a resistance,, 
they are then charged in the opposite direction and 
allowed to discharge again, and this process is repeated 
several times. The object of this " forming" process is 

Fig. 14.— Accumulator in glass vessel, showing arrangement of plates. 

to increase their capacity by the production of a thick 
layer of lead peroxide upon the plate which is positive,, 
and of spongy metallic lead upon the negative. In the 
other type of cell, the plates are perforated grids of lead^ 
and the holes in the positive plates are filled with a 
paste made of red lead or peroxide of lead and dilute 


sulphuric acid, which sets fairly hard in them. Those 
in the negative plate are filled with a paste of litharge 
and sulphuric acid. The plates, formed into "sections" 
of positive and negative plates arranged alternately, are 
placed in the cells, and these are filled up with dilute 
sulphuric acid, of sp. gr. I'lyo, and they are ready for 
the first process of charging. This is called " forming " 
the cells, and consists in charging them for a very long 
period, say about thirty hours. When a cell has just 
been charged it will be found to have an electromotive 
force of nearly 2*5 volts, but the working voltage is 2 
volts. When the cells are discharging, the electromotive 
force is maintained till about 75 per cent, of the ampere 
hours that the cell will give has been done, and then 
the electromotive force falls quickly. 

It may be taken as a general rule that as soon as the 
electromotive force of a cell falls below 2 volts or i-8 at 
the lowest that cell should at once be recharged. If it 
is not attended to the cell becomes injured, and sul- 
phates of lead are liable to form which increase its 
internal resistance and decrease its storage capacity, 
and the grids are liable to buckle and lose their paste. 

It is not easy to give much idea of the storage capa- 
city of these cells, but a well designed one should be 
capable of giving about 5 to 7 ampere hours per pound 
of lead. 

The internal resistance of a storage cell is almost 
infinitesimal when it is in good order, and may generally 
be neglected in calculations concerning them unless a 
very large number are coupled up in series, since the 
current that may be taken out of the cell is limited by 
other considerations. It is this low internal resistance 
which makes them so useful for cautery purposes, where 
large currents are needed. As the paste is Hable to 


leave the plates if too large a current be taken from a 
cell, it follows that the practice of flashing the cells to 
see if they are in working order, viz., connecting their 
poles through a short piece of copper wire for an instant 
is very injurious to the life of a cell for this treatment 
produces a rush of current of considerable magnitude, 
and it tends to loosen the paste and set up deleterious 
sulphating. Accumulator cells must never be allowed 
to fully discharge themselves, they should be tested 
from time to time with a voltmeter, and as soon as the 
electromotive force of a cell sinks to below 2 volts it 
must be recharged. 

The difficulties found in working with accumulators 
of the type having "pasted" plates has caused some 
makers to return to the original type of accumulator as 
invented by Plante, where no pastes of the oxides of 
lead are used. 

The Lithanode Cell" is another form of secondary 
cell which works well, and is made in several different 
sizes and in. portable sets some of which are admirably 
adapted for medical purposes, particularly for lighting- 
small incandescent lamps. These cells are light and 
compact, and the company undertake all arrangements 
for recharging and maintenance at a small cost. They 
make small accumulator cells weighing only four 
ounces, which might prove useful for medical batteries 
wherever the recharging can be done without trouble 
(fig. 16), and also smaller cells whose weight is only twa 
ounces and a half. In the lithanode cells the positive 
plates consist of slabs of a very dense lead peroxide 
compound enclosed in a metallic framework, and they 
are free from some of the faults common to the 
" pasted " plates. 

* The Lithanode Electric Storage Co., Harve}- Buildings, 427A. 
Strand, W.C. 



60. Table of batteries. — The appended table of 
batteries may be of service. The internal resistance, 
though a most important factor in calculations as to the 
discharging rate of a cell, varies with the size of the 

Fig. 15.— Fi^e-cell lithanode cell with detachable lamp. 

cell. An internal resistance which at all nearly 
approaches one ohm makes a battery useless for cautery 

The resistance of the bichromate cell depends upon 



its size and make, generally speaking in the types 
manufactured for cautery heating and for lighting it is 
made as low as possible and is about '15 ohm. The 

Fig. 16. — Lithanode testine cell. 

resistance of Daniell's cell depends on its size and the 
density of the porous pot used, and varies from about 
•3 to 2 ohms. A quart Grove or Bunsen cell has a 
resistance of about -15 ohm. The Edison-Lalande 



battery is also specially constructed for cautery work, 
and in the larger forms the internal resistance maybe 
brought as low as "05 ohm. That of a Leclanche cell 
varies from about -5 in the largest sizes to two, three, 
or five ohms in the smallest ones. The internal resist- 
ance of the various dry cells is given by the makers as 
from •! to I ohm according to size. The secondary 
batteries all have a very low internal resistance indeed, 
according to the number and size of the plates. 

Table of Batteries. 






Force, Volts. 

1. Bichromate. . 

2. Daniell . . . 

3. Bunsen . . . 

4. Edison-Lalande 

5. Leclanche . . 
6 Hellesen . . . 

7. Secondary battery 


Dilute sulphuric 
acid, 1-8 

Zinc sulphate or 

dilute sulphuric 

acid, 1-12 

Dilute sulphuric 

Potassium hy- 
drati* 40 per cent. 


chloride solution, 



chloride and 


Dilute sulphuric 
acid,sp. gr. i-i-o 

Chromic acid 


Strong nitric 

Cupric oxide 


Lead peroxide 









Cells which have a low internal resistance are much 
more easily run down by any accidental short circuiting 
than those with a high resistance. If an accumulator 
cell with an internal resistance of -05 ohm be short 


circuited, it may discharge at a rate of 40 amperes, 
which will very quickly exhaust it, and most likely 
damage it seriously as well. 
61. On the choice of a medical battery. — In 

choosing a battery for medical purposes the essentials- 
are to have one which is efficient and does not require 
frequent attention. For a complete outfit two separate 
batteries are required, one for diagnosis and treatment, 
and one for lamps and cauteries. In many cases it is 
necessary to carry a battery to the houses of patients, 
therefore, portability must not be lost sight of. Medical 
batteries are sold by electrical instrument makers con- 
sisting of from 25 to 40 cells arranged in a case and 
fitted with commutator, current collector, galvanometer 
and induction coil. These are quite suitable for testing 
the reactions of nerve and muscle, for general medical 
treatment and for electrolysis. The cells used are 
usually either small Leclanche or "dry" cells. Owing 
to their smallness their capacity is not large and they 
cannot long give out large currents without becoming 
exhausted. With proper care they may be counted 
upon for a year or two for all ordinary purposes of test- 
ing and treatment, including occasional use for the 
electrolysis of neevi, which demands fairly large cur- 
rents, and then will require recharging or renewal. 
The best plan perhaps is to use small dry cells, and 
renew them altogether when exhausted. The medical 
Leclanche cell costs more on account of its ebonite case,, 
these if returned can be allowed for, but it is better not 
to be troubled with them. The dry cells cost only 
about eighteenpence per cell. For working the induc- 
tion coil in portable medical batteries two cells of larger 
size are fitted ; these run down more rapidly than the 
others and require renewal more frequently. Catalogues 



Fic. i;.— Schall's combined battery, 

may be consulted by those wishing to purchase any- 
thing of the sort. The details of the fittings of these 



batteries vary with the different makers, but instruc- 
tions for use are usually supplied with the instruments. 
For heating cauteries and for electric light instruments, 
a four cell accumulator arranged with a switch to con- 
nect the cells into two pairs in parallel, or into four 
cells in series, and provided with an adjustable resist- 

FiG. iS. — Combined medical battery.* 

ance is the best battery, unless the recharging is an 
obstacle. In that case a four cell bichromate battery of 
large size, with proper connections, will serve the same 
purpose. f For further details of lamp and cautery 

* L. Miller, 93 Hatton Garden, W.C. 

t K. Schall, 55 Wigmore Street, price £6, 


outfits see Chapter XV. There is no need to have a 
fixed installation in the consulting room as well as a 
portable combined battery, for the latter will serve at 
home as well as in the houses of patients, and as all. 
battery cells tend to deteriorate in time whether they 
are used or not, there is twice the cost of maintenance 
with two batteries that there is with one. Naturally it 
is convenient sometimes to have a fixed installation of 
large cells at home, as well as a portable set ; but it 
is more economical and less troublesome to have few 

An exception may be made in favour of a separate 
induction coil. The coil is more often required for 
purposes of treatment than a constant battery ; and it 
is a convenience to have a light-weight induction coil, 
for then the labour of transporting a heavy combined 
battery will sometimes be saved. 

It may be useful here to mention the best types of 
cell for the various purposes to which they may be put 
by medical men : — For general medical purposes of testing 
and treatment, 25 to 30 dry cells of small size. For 
working induction coils, one or two dry cells of larger size. 
For medical lamp instruments, four or five cells of a 
secondary battery, or six large bichromate cells. For 
cautery purposes, two secondary cells, or large bichromate, 
or Edison-Lalande cells. For recharging accumnlators, 
Bunsen or Daniell cells ; for method of procedure see 
end of next paragraph. 

62. Care of batteries. — The trouble of keeping 
batteries in order is commonly put forward as an excuse 
for neglecting electricity in medical practice. It is 
important in buying a battery to choose one which will 
remain in good order without much attention. On this 
account acid cells are to be avoided as much as pos- 


sible. Small dry cells should always be preferred for 
portable batteries. In country places some large bi- 
chromate cells may be a necessary evil for cautery and 
lamp work, but wherever dynamo currents can be had 
for charging purposes an accumulator is better. 

To keep a bichromate cell in good order it must be 
attended to. If its action fails and the liquid is found 
to be dark green in colour it must be renewed, if it is 
still orange a dose of strong sulphuric acid will restore 
it for a time. The cell must be taken down occasion- 
ally, the carbon plates soaked in water and brushed 
with an old tooth brush, and the zincs must be also 
washed clean and amalgamated ; to do this they should 
be scraped fairly smooth and wetted with dilute acid 
and then some mercury should be well rubbed into them 
with a piece of old leather or wood. The surface when 
properly amalgmated looks as bright as silver and 
should appear to be whetted by the mercury at every 

The zincs must never be left in the chromic solu- 
tion when not in use, as it attacks zinc with great 

To charge an accumulator from a primary battery, 
the latter must have an electromotive force greater than 
that of the cells to be charged. For a two-celled accu- 
mulator, five Daniell cells, three bichromate, or Bunsen 
cells, or seven Edison-Lalande cells are required. The 
charging cells should be large, the process is as 
follows : — The primary battery having been freshly 
charged, coupled in series, § 46, and tested to see that 
it is in good order, it must be attached to the accumu- 
lator, positive pole to positive pole, and negative to 
negative. Current will then pass to the accumulator 
from the battery so long as its electromotive force keeps 


up above that of the secondary cells. The current will 
slowly diminish as the primary cells run down ; when 
the electromotive forces of the primary and secondary 
cells are in equilibrium no current passes in either 
direction ; if the primary cells run down more the 
current will set in the other direction and the accu- 
mulator may discharge itself through them and thus 
defeat the object of the charging operation. 

The operation must accordingly be watched and 
stopped before the charging current has fallen to zero. 
A suitable ammeter (Chap. V.) will show the magnitude 
and direction of the current which is passing. By 
noting the magnitude of current at intervals during the 
charging process, an idea is obtained of the amount of 
the charge. For example, suppose the duration of the 
charge be six hours, and the current during the first 
hour be- three amperes, during the second and third 
hours two amperes, during the fourth one ampere, and 
during the fifth and sixth half an ampere, then the 
charge will be in amperes for each hour, 3, 2, 2, i, |, -|, 
or 9-ampere hours. 

The method of charging accumulators from the elec- 
tric light mains is described in the next chapter. See 
also Mr. J. T. Niblett's little book, Portative Electricity, ■■' 
for much valuable information upon the whole subject 
of the management, care and charging of small accu- 

The utmost vigilance must be perpetually exercised 
to guard against accidental or intentional short circuit- 
ing of any battery. Few batteries will stand short 
circuiting for many minutes ; the dry batteries most 
used in medical practice are particularly sensitive to it. 
Short circuiting may easily occur if the electrodes are 

* Biggs & Co., Salisbury Court, Fleet Street. 


carelessly thrown down after use, and should happen to 
lie in metallic contact wdth each other. 

When a battery has been dismounted and put to- 
gether again, especially if it has many complex connec- 
tions, there is a danger that the positive pole may have 
been accidentally connected to the binding screw 
marked negative and vice versa. This is sometimes the 
case even when the repairs have been done by an in- 
strument maker. This is an important point because 
confusion of the poles may lead to serious mistakes and 
even to injury to the patient. All risk can be done 
away w4th by the use of some method of testing the 
polarity of the electrodes. It is easy to improvise one. 
A piece of wet litmus paper on a sheet of glass, will 
show by changes in colour at the electrodes which is 
the positive and which the negative pole. The ends of 
the wires from the battery must be rested on the paper 
for a few moments, electrolysis will take place and the 
litmus w^ill be reddened by the acid liberated at the 
anode or positive pole, and will turn blue at the kathode 
or negative pole. Other reagents have been proposed, 
for example, a solution of phenol-phthalein in dilute 
alcohol answers very well, giving a purple red colour 
at the kathode or negative pole. 



Dynamo Electricity. 

The Dynamo Machine. Current Generators. The electric lighting 
mains. Direct and alternating current. Current from the main 
for medical and surgical applications. Regulation by resist- 
ances. Transformers. Dynamotors and motor dynamos. 

63. The dynamo machine. — Commercial applica- 
tions of electricity on a large scale would not be possible 
without the dynamo, because the primary battery, con- 
venient as it is for some purposes, is altogether unequal 
to the work of producing electrical currents abundantly 
and cheaply. With the wide spread distribution of 
electricity from house to house by the electric lighting 
companies, the field of utility of the primary battery 
grows more and more restricted, and the current from 
the main is called into service for medical purposes 
wherever it is found. In this chapter the production of 
current by means of the dynamo machine, and other 
generators, and the technical details of adapting electric 
lighting currents for surgical and medical purposes will 
be considered. 

In the near future there will not only be a great 
increase of public supplies of electricity for illuminating 
purposes, but the advent of electrically driven motor 
cars to take the place of horse traction will probably 
lead to the setting up of private dynamo sets in country 
places, and especially by medical practitioners, who will 
be glad to get rid of the troubles associated with horses 



and to have instead an engine which will serve both to 
give them electric light at home and motive power 
abroad. A dynamo is a machine for converting 
mechanical energy into electrical energy by causing 
conductors to move in a magnetic field. It follows 
from § 40 that currents are induced in moving con- 
ductors if their movement is of such a kind as to cause 
them alternately to approach and to recede from a 
magnetic pole, and in a dynamo there is a fixed mag- 
netic part or "field magnet" and a moving system of 
conductors or "armature" which rotates in the mag- 
netic field between the poles of the field magnet. 

64. The field magnet. — In the early days of dynamo 
electric machines this consisted of a permanent steel 
magnet or magnets. Instruments of this kind still 
survive, and under the name of "magneto machines" 
have had a certain vogue for medical purposes. Electro- 
magnets have now completely superseded permanent 
magnets for dynamos, and though the shapes seem to 
vary in different types of machines, all are essentially 
horseshoe magnets or groups of these. Oersted's dis- 
covery (§ 24 and § 26) of the magnetic properties of a 
wire carrying a current led naturally to the invention of 
the electro-magnet, for it was found that a soft iron 
"core" would be rendered temporarily magnetic by 
surrounding it with a spiral winding of copper wire 
and passing a current through the wire. For an 
account of electro-magnets see " The Electro- Magnet 
and Electro-Magnetic Mechanisms," by Silvanus P. 

The field magnet of a dynamo is an electro-magnet 
magnetised or "excited" by the passage of a current 
through the coils of wire wound upon it, the current for 
the purpose being usually taken from its own armature. 



It is found that a slight permanent magnetism exists in 
all field magnet cores and this is sufficient to start small 

Fig. 19.— Series Wound Dynamo. 

Fig. 20.— Shunt Wound Dynamo, 

currents in the armature when it is rotated. These 
currents are made to traverse the field magnet and they 



strengthen it so that it reacts more strongly on the 
armature until by the continuance of this mutual re- 
action between the armature and the field magnet the 
latter becomes fully magnetised. Thus a dynamo is a 
self exciting machine. The armature is mounted on a 
shaft provided with a pulley for the purpose of rotation 
and at one end of it is fixed the commutator which is 
built up of a number of copper or brass segments insu- 
lated from the shaft and from each other ; the ends of 
the coil or coils of wire which form the armature are 
connected to these commutator segments, and when the 
armature is in rotation the segments pass in turn under 
the end of two collecting brushes which make contact 
with them. The commutator is a necessary part of a 
continuous current dynamo, for it serves to rectify the 
alternate currents generated in the coils during their 
rotation and delivers them to the field magnet coils and 
to the outside circuit as a series of impulses in one 
direction. When the whole of the current from the 
collecting brushes passes first through the field magnet 
coils and then through the outer circuit, the dynamo is 
said to be " series wound," the two portions of the 
circuit being in series, whereas a " shunt wound '^ 
dynamo has the field magnet coils in parallel or in 
"shunt" with the outer circuit (figs. 19 and 20). Each 
of these windings present advantages for certain pur- 

65. Power for dynamo driving.— A great increase 
in the use, by medical men, of electrical currents from 
storage cells has sprung up from the application of 
Rontgen Rays to diagnosis in surgery and medicine, 
and the use of storage cells brings the need of current 
for charging them. Primary batteries are of no use for 
driving the large induction coils which are commonly 


■employed for X Ray work, and to use them indirectly 
for charging accumulators soon becomes tiresome. In 
many places the recharging can only be done by sending 
the accumulators to a dynamo station at a distance and 
the transportation of accumulators is expensive and 
troublesome and is by no means conducive to the long 
life of the cells. On the other hand it is rather a 
formidable undertaking for a medical man to set up 
a private dynamo for charging his accumulators, and 
•especially so because it is difficult to procure a plant 
which is satisfactory without also being too big. One 
needs not only the dynamo, but also the power to drive 
it, and it is difficult to find good engines of very small 
power, as small machines are apt to be as expensive to 
make as bigger ones would be, and there is no large 
demand for them. 

Manual power, windmills, water motors, hot air 
motors and gas and oil engines have all been applied 
to the driving of dynamos. In any particular case the 
local conditions will help to decide which is likely to be 
the most convenient source of power. To charge an 
accumulator from a dynamo is not so entirely simple a 
matter as may be supposed, and will be referred to 
again below. The E.M.F. of the charging source must 
be maintained steadily above that of the cells to be 
-charged, for if this is not done the cells will discharge 
back through the dynamo, with a result quite opposite 
to that desired. On this account manual power is apt 
to be too unsteady for charging purposes. By adapting 
a bicycle and so making use of pedal power, the Crypto 
Cycle Company of Clerkenwell have contrived a fairly 
useful apparatus for dynamo driving, and it is interest- 
ing to note that the electricity required for charging 
accumulators in the Soudan campaign for Rontgen Ray 


work was generated by means of an apparatus of this 
kind, a tandem bicycle being so converted as to drive 
the dynamo by means of a belt from the hind wheeL 
See the illustrated paper by Surgeon-Major Battersby 
in the Archives of the Rontgen Ray for February, 1899. 

In many places a small windmill would be of great 
use for charging a few storage cells, and probably a 
small outfit comprising a windmill and dynamo might 
sell advantageously in country places. 

Where there is a cheap water supply a water motor 
can be made to work with very little trouble, and would 
be a useful contrivance, but water motors consume 
much water. There are several forms of water motors 
in small sizes, which can be had from the makers of 
philosophical instruments. 

The hot air engine sold by Messrs. Norris and Henty"'^ 
under the name of the Robinson Hot Air Engine, and 
another form sold by Messrs. Baird and Tatlock are 
handy little things, but only give about one twenty-fifth 
of a horse power, and it is worth no one's while at 
present to make a dynamo of that small power, which 
shall convert the mechanical into electrical energy with 
any approach to efficiency. 

Messrs. Vandervell, Thorpe Works, Netting Hill, W.,. 
make a gas engine of one-eighth horse-power which can 
be used to drive a dynamo for charging storage cells. 
It is a good little engine, and would probably answer 
for charging purposes quite well in the hands of anyone 
who was willing to take a little trouble to get to know it 
thoroughly. They quote for the engine alone £^ los., 
or with dynamo mounted on iron bed plate £'j ys^ 
They recommend, however, a small further outlay so as 
to provide a better dynamo, which would make the 
* 36 Upper Thames Street, E.G. 



combination work more steadily. In the larger size of 
one-half horse-power one begins to reach practical and 
good gas and oil engines. The Gardner Engines, for 
gas and oil (Norris and Henty as above), cost /'15 and 
£1^ respectively at this power, and can be specially pro- 
vided with dynamo, pulleys, belts, etc., complete at 
£2^ los. and £1^ los. With one of these sets the 
charging of storage cells can be effectively dealt with. 
The Pittler Company (144 High Holborn) also list a 
"one man" power gas-engine at nine guineas. When 

Fig. 21.— Vandervell's Gas Engine. 

charging an accumulator from a dynamo the possibility 
of an unexpected stoppage of the machine must be 
borne in mind. To meet this possibility automatic 
switches have been contrived which at once cut off the 
cells from the dynamo circuit if anything goes wrong. 
This is necessary to prevent the charge already accu- 
mulated in the storage cells from running down through 
the dynamo circuit to the probable damage both of 
dynamo and cells. When the dynamo is running its 
polarity must be verified (§ 62) before joining up the 
cells to it. 


66. Current from electric lighting mains. — It 

will be seen from the preceding paragraphs that the 
generation of electricity in small quantities in one's own 
household is surrounded with difficulties. Those who 
live in a place where there is a public supply of elec- 
tricity are spared these difficulties and only require to 
know the capabilities of the supply at their command 
and how best to adapt it for their professional require- 
ments. For this it is necessary in the first place to 
know whether the public supply is direct or alternating, 
secondly, the voltage or pressure of the supply : thirdly, 
in the case of alternating current, the periodicity or fre- 
quency of the alternations. In Appendix A is set forth 
a list of the public supply stations in Great Britain and 
Ireland, with particulars of these details. 

The difference between direct and alternating current 
consists in the former being a steady flow of current 
from the one conductor or lead through the lamp (or other 
appliance) to the other. The one wire is always 
positive, the other always negative. In the alternating 
supply the current flows in a series of pulsations in both 
directions, each wire being in turn either positive or 
negative. The pressure at which electric lighting 
currents are supplied to houses is usually loo volts, in 
some places 103, 105 or no. At the present time a 
gradual change to 200 as the standard pressure of 
supply is taking place, with the object of saving ex- 
pense in mains. At 200 volts a given current represents 
twice as much energy (§ 39) as the same current at 100 
volts, so by doubling the voltage of supply the conduc- 
tors are enabled to carry a double load without the need 
for increasing their sectional area. See § 29 on Resist- 
ance of Conductors. There is no special advantage to 
the consumer from the higher voltage, but rather the 


reverse, but the advantage to the supply companies in 
the saving of capital outlay on copper for mains is 

The uses to which the current from the mains may be 
applied are as follows : — 

1. To illuminate cystoscope lamps and other small 
lamp instruments. 

2. To heat a galvano-cautery. 

3. To drive dental and other small motors. 

4. To operate large induction coils for X Ray work, 
ozonisers, &c., and medical coils. 

5. To charge accumulators. 

6. To replace medical batteries in the treatment of 

For all these purposes it is important to know whether 
the supply is direct or alternating, because the nature 
of the apparatus will depend primarily upon this point. 
Either direct or alternating current can be used for 
heating a cautery, for lighting up lamps or for driving 
motors. The alternating current cannot be made to 
charge accumulators nor to work large coils, nor to 
replace a constant current battery. It can, however, be 
made to take the place of a medical induction coil with 
certain limitations. Perhaps, it may help to make the 
differences between the two kinds more readily intelligi- 
ble if it be borne in mind that the direct current is 
more like a battery current, and the alternating current 
more like the current of an induction coil. It will be 
convenient to take two cases and deal exhaustively with 
each ; one, the case of a medical man with direct current 
at command, and the other, that of one with alternating 
current laid on. 

67. Direct current resistances. — In almost all 
applications of the current to medical practice the first 


need is for means of reducing the pressure. The pres- 
sure of supply (loo volts or upwards) is too great for 
any of the medical purposes just enumerated, except for 
the driving of some electro-motors. In order to reduce 
the pressure resistances are employed, for by means 
of the resistances in a circuit the magnitude of the 
current in the circuit can be regulated [see § 31, Ohm's 
law). Thus a resistance of 100 ohms in a circuit of 
100 volts will prevent the current from exceeding one 
ampere and a resistance of 100,000 ohms will cut down 
the current to one milliampere and so on. 

It is important to distinguish between the effect of a 
resistance in cutting down the current in a circuit, and 
its effect in lowering the voltage in a circuit or portion 
of a circuit. In § 45 when treating of internal resist- 
ance an attempt was made to draw this distinction, and 
it must now be repeated that the effect of a resistance 
upon the voltage in any part of a circuit is a relative 
one, that is to say the fall of volts in a part of a circuit, 
such as a resistance, depends upon the resistances of the 
other parts of the circuit, and may be estimated by 
comparing the resistance of the part under consideration 
with the resistance of the rest of the circuit. For in- 
stance, take a resistance of 99 ohms interpolated in a cir- 
cuit of 100 volts, when the resistance of the remainder of 
the circuit is very small, say, for purposes of illustration, 
one ohm, then the drop of volts in the resistance will be 
99 volts. But if four such resistances be inserted in 
different parts of the same circuit then the drop in volts at 
each resistance will no longer be 99 volts, but will be 
one quarter of that amount, and the fall in the potential 
from 100 to o will take place in four steps of about 25 
volts, one at each resistance. It follows from this that a 
resistance intended for regulating the voltage in any 


part of a circuit must be made proportional to the 
resistance of the circuit to be regulated. If the resist- 
ance of the part to be regulated is 50 ohms then a 
resistance of 50 other ohms will halve the voltage 
acting on it, but a resistance of 50 ohms will not 
equally halve the pressure if the other part has a 
resistance of 950 ohms, for in this case the fall in volts 
at the first resistance would only be one-twentieth of 
the total voltage of the circuit, while the second portion 
would bear a voltage of nineteen- twentieths of the total. 
A resistance which is suited for the regulation of the 
current of a lamp will not serve to regulate current 
through the human body. In the first case a few ohms 
will suffice, in the latter a few thousand ohms are 

68. Resistance instruments. — It was stated in 
§ 39 that the energy expended when a current passes 
through a resistance appears for the most part in the 
form of heat. Resistances, therefore, become heated 
when in use, and the heating effects must be carefully 
borne in mind and the resistances designed to carry the 
currents they are intended to regulate without excessive 
heating. A resistance suitable for a current of a few 
milliamperes might be burnt out if a current of one 
ampere were passed through it. As a general rule the 
larger the current to be controlled the bigger and 
stronger and more expensive the controlling resistances 
become. From their cheapness and convenience incan- 
descent lamps are often useful for resistances as they 
are not injuriously affected even by great heating, and 
in almost all resistances for medical use an incandescent 
lamp of eight or sixteen candle power forms part of the 
circuit, being combined usually with a coiled wire re- 
sistance which admits of adjustment. On a circuit of 


loo volts a sixteen candle power lamp will cut down the 
current to about -6 of an ampere. An eight candle lamp 
to '3, and a thirty-two to i-2 amperes. By always work- 
ing through a lamp the maximum current can be kept 
down within these very moderate limits and thus trouble 
with the safety fuses and risk of damage to the galvano- 
meter coils or other delicate apparatus may be avoided. 
As a rough approximation the resistances of incandes- 
cent lamps may be taken as follows : — For loo volts ; an 
eight candle lamp 320 ohms, a sixteen 160 ohms, a 
thirty-two 80 ohms. With 200 volt lamps the resistances 
are double of these. The ordinary way of using a 
resistance is to put it in series with the apparatus to be 
protected. The whole current then passes first through 
the resistance and then through the apparatus regulated. 
But another way of using resistances is to have them as 
a shunt or bridge to the piece of apparatus, the current 
dividing and part passing by the one channel and part 
by the other. When two circuits are arranged in this 
way, in parallel, either of them is said to be " in shunt " 
to the other, or "shunted by" the other. Arrangements 
of resistances in series or in shunt to apparatus are 
often useful, or tw^o resistances may be used in series 
with each other, the patient (or the piece of apparatus) 
being arranged as a circuit in shunt to one of them, and 
figure 22 shows such a combination of resistances. The 
current from the main passes from the positive pole of 
the supply through a switch to A. From A to B is a 
resistance of wire, B is a lamp which the current 
traverses to reach the negative pole, after passing 
through a fuse. Thus there is formed a closed circuit 
through the two resistances of the wire coil and of the 
lamp with a fall or slope of potential between A and B 
and a further fall through the lamp at B, the total fall 



being from loo volts to zero on a loo volt circuit. The 
circuit for the patient, or instrument, is arranged in a 
shunt to the wire resistance, and the voltage, acting 
upon it, will be varied by moving the traveller C along 
its metal slide. Let us suppose that the coils depicted 
are 450 in number, and that their resistance is nine times 
as great as that of the lamp B, then assuming our 
pressure at the main to be 100 volts, the drop of volts 
in the lamp will be 10 volts and in the coils 90 volts. 
With 450 coils in the wire the fall of volts is one-fifth 

Fig. 22.— Plan of resistance in shunt to a pa ient. 

of a volt per coil, that is to say there will be a potential 
difference of one-fifth of a volt between any coil and the 
next. If the coils were 4,500 in number then the poten- 
tial differences would be as one volt for every 50 coils, 
and so on. The potential difference between C and B 
through the shunt circuit would increase as the traveller 
C was moved further from the B end of the coil, because 
it would "tap" the slope of potential at a higher level, 
so to speak, and the more numerous the coils of A and 


B the more finely could the volts be adjusted to suit 
any needs of the shunt circuit. 

With certain structural variations, chiefly in the 
number of the windings and the thickness of the wire, 
this method will suit all the cases which require a low 
pressure to be obtained from the electric light mains. 
The lamp acts as a safety resistance and determines 
the maximum current which can pass through the 
apparatus. A certain latitude is afforded by the use 
of lamps of various candle power for the safety re- 
sistance. When the current is to be applied to the 
lighting of a small surgical lamp which requires, say, 
an ampere, the safety lamp must be of such a char- 
acter as to permit that current to pass it. When a 
cautery is to be heated no lamp is arranged in series 
with the coil and the various parts must be on a much 
larger scale, because they have to waste energy at the 
Tate of two horse-power when in use, and the current of 
from five to twenty amperes which a cautery requires 
lias considerable heating effect upon the wires which 
lead to the cautery as well as upon the cautery burner 
itself. The immediate application of a direct current 
from the mains to the commoner requirements of medical 
practice is fully met by a set of resistances arranged 
to give slopes of potential, with sliding contacts for 
varying the pressure in the shunt circuits in which the 
patient or the apparatus is arranged. These things can 
be had mounted ready for fixing to a wall or table from 
Mr. Schall (see fig. 23). 

69. To charge accumulators. — Unless a special 
point be made of working only from the main direct, 
one may use the direct current to charge accumulators 
in the first place ; the accumulators can then be de- 
tached from the mains and used independently. In 



the former case there will still remain the need for 
providing a portable apparatus to take to a patient's 

Fig. 23. — The terminals at F are for charging accumulators, or for working a 
medical coil; the terminals marked +, — , for direct applications to patients. 

house. Although a desire for absolute uniformity of 
practice, or the idea of saving oneself trouble, might 
make one v^ish to use current from the mains only, 


without any accumulators, the advantages on a prac- 
tical side all lie in a combination of the two methods, 
that is to say in the use of accumulators for some pur- 
poses, and in direct applications of the current from the 
mains in others. Thus by far the simplest way, and the 
cheapest, for lamp and cautery work, is to charge a 
portable accumulator from the mains, and then to use it 

Fig. 24. — Charging an accumulator from the electric light mains. 

detached, for the lamps or cautery. Many surgeons 
only use electricity for these purposes and with a small 
portable accumulator and a plug arrangement for re- 
charging it, they can be fully equipped at a small 

To charge an accumulator from the direct current 
mains is easy. A plug of special construction (fig. 25) 
with a lamp is needed. The current passes through the 


lamp to the accumulator, as shown in fig. 24, the 
lamp serving as a protecting resistance. The accumu- 
lator is connected by wires to the two binding screws 
shown in fig. 25. To charge from a concentric wall 
plug, or from an Edison-Swan screw lamp socket is 
best, because such a plug can only fit into its socket in 
one way and the positive and negative terminals are 
always the same [see also p. 78). With a lamp socket of 
the ordinary bayonet-catch pattern there would be a 
right and wrong way and the polarity of the terminals 

Fig. 25.— Lamp resistance for charging secondary cells from the mains. 

needs testing each time (see § 62, pole testers). A rough 
and ready way to test the direction of the current 
when charging secondary cells is to notice the bright- 
ness of the lamp when the accumulator is coupled 
in, for when joined correctly for charging the bright- 
ness of the lamp is lessened, whereas the lamp glows 



more brightly when the connections through the accu- 
mulator permit of its discharge. If the experiment of 
connecting up in each direction be tried a few times the 
difference in the brightness of the lamp will soon be 

When the charging of the cells from the mains is to 
be done regularly it may be worth while to have the 
charging terminals connected to some one of the house 
lamps which is in regular use, in order not to waste 
energy. As the electromotive force of the cells which 
are under charge is opposed to that of the charging" 
circuit, the lamp will be dimmed to a certain extent by 
the counter-electromotive force of the cells, this can be 
met by using a lamp of low^er voltage. Thus on a loo 
volt circuit a go volt lamp in series with an accumulator 
of four cells (8 volts) would be brought to full incandes- 
cence and would give a good light while the accumu- 
lator was being charged. 

70. Alternating currents. Transformers.— The 
general limitations of the alternate current supply for 
medical work are given on page 89. There the alternating 
current was compared to the induction coil current, for 
which see Chap. V. It cannot, however, be conveniently 
used for general purposes in testing nerves and muscles 
nor in treatment except through the medium of a bath 
(see Chap. VIII., "The Electric Bath") as when applied 
to the skin in the usual way by means of pad electrodes 
the sensations it causes are unpleasant. 

The main feature of convenience which alternate 
currents have lies in the ease with which they can 
be made to induce fresh alternating currents at any 
desired voltage. With continuous currents, as we have 
just seen (§ 68), the voltage of supply can be cut down 
by means of resistances, which may also be used with 



alternate currents, but by means of a transformer the 
pressure of supply of an alternating current can be 
changed into any other pressure, higher or lower, as may 
be desired, and that without the waste of energy which 
occurs in the case of resistances. Thus by a trans- 
former the energy represented by a current of one 
ampere at loo volts can be transformed into a current 
of loo amperes at one volt, or into a current of one- 
hundredth of an ampere at 10,000 volts, subject only to 
small losses in the apparatus. 

Fig. 26. — Graduated transformer. 

The principle of the transformer is that of the induc- 
tion of a current in a wire by a variable current in a 
neighbouring wire (§ 40), and the transformer consists 
of an iron core wound with two distinct windings of 
insulated wire. These may be called the primary 
and the secondary windings, and the variable E.M.F. 
impressed upon the primary when it is connected to 
a system of alternate current supply will induce a vari- 
able E.M.F. in the secondary, having a voltage which 
will depend upon the ratios of the number of turns of 
wire in the primary and secondary coils. 




The commonest type of transformer for medical use 
is one which is used to convert a small current at loo 
volts into a larger current at two or four volts for 
cauteries, or at eight or ten volts for small incandescent 
lamps, or for use in the electric bath, while, occasionally, 
transformers may be required to give out high pressures 

Fig. 27. — Woakes' transformer. 

of many thousand volts for generating ozone, or working 
Tesla high frequency coils. 

A well-known type of transformer for medical use is 
Woakes' transformer. It has several secondary coils 
all wound upoii one bobbin ; one for cautery to give 


about two volts and wound with thick wire to carry a 
heavy current without heating ; one for small lamps, 
and one for therapeutic purposes. Each secondary has 
its own terminals, and all are excited by one primary 
coil. Regulation is effected by a sliding arrangement 
which serves to bring the secondary coils towards the 
primary coil or away from it. In other forms of 
medical transformer the iron core is not straight as 
in Woakes' pattern, but is a circular ring of laminated 
iron. This is more efficient electrically, but less con- 
venient for regulation. Fig. 26 shows a ring trans- 
former which has a secondary tapped and brought out 
to binding screws at intervals, thus affording a means 
of obtaining a great variety of voltages from one 

28.— Motor Dynamo. A motor and a dynamo combined on one axle. 

instrument. Others again are made with a moving 
arm which takes up into circuit more or less of the 
windings of the secondary, and so gives very good 
regulation of voltage. 

71. The conversion of direct current into alter- 
nating and vice-versa. — It sometimes happens that a 
consumer upon one system of supply desires something 
which can only be had from the other system ; thus a con- 


sumer in an alternate current area may wish for direct 
current to charge accumulators, or a consumer on direct 
current may wish for alternate current for an electric 
bath or for use with high voltage transformers. Various 
devices have been proposed for fulfilling these objects ; 
for example, a motor driven by the current supplied in 
the district is made to drive a dynamo built to give out 
the kind of current required. In some cases the two 
machines have been combined into one compound 
machine with greater or less success. The General 
Electric Company stock these under the names of dyna- 
motors or motor dynamos, and supply them for battery 

Fig. 29. — Dynamotor. Two sets of windings upon one armature. 

charging ; that is to say for the conversion of a continuous 
current at high voltage into a continuous current of 
greater magnitude at a lower voltage, and for bell- 
ringing, that is for generating an alternating current of 
low voltage from a direct current at 100 or 200 volts. 
When the conversions have to be from alternating o 
continuous current one must have recourse to two 


separate machines, an alternate current motor driving a 
direct current dynamo. The apparatus can easily be 
contrived but owing to its cost medical men are as a 
rule content to do without it, there is therefore no good 
ready-made instrument of this type as yet on the 
market. The Langdon-Davies Motor Company make 
a good motor for alternating currents, from one-half 
horse power upwards, and one of their instruments con- 
nected by belt or otherwise to a direct current dynamo 
of corresponding size will effect the conversion of alter- 
nating into direct current. The dynamo must be 
wound to suit the voltage and current required from it. 



The Induction Coil. Conducting Wires. Binding Screws. Elec- 
trodes. Current Collectors. Commutators. Regulation of 
Current. Galvanometers. 

72. The induction coil. — One of the most interest- 
ing of the early observations in connection with electro- 
magnetic induction was, that shocks and sparks could 
be produced from a single galvanic cell if its circuit 
contained spiral coils of wire. Indeed, it is possible 
that Faraday's researches into the phenomena of induc- 
tion may have been started in that direction by a 
question asked of him at the Royal Institution, as to 
why a shock was felt when a circuit containing an 
electro-magnet was broken, although no shock was felt 
if the circuit contained no magnet nor coils of wire. In 
§ 42 it has been mentioned that these effects depend 
upon the self-induction of the circuit ; and very shortly 
after the publication of the researches of Faraday and 
of Henry in 1831 and 1832, the subject was taken up by 
others, and coils were made by Page, Sturgeon, Callan, 
and others, which were the prototypes of the modern 
induction coil."'' 

The peculiar physiological effect or shock which 
these induction coils produced soon led to their 
application to medical treatment, and in 1837 ^ 
machine contrived for this purpose by a Mr. Clark, 
was figured! in Sturgeon's Annals of Electricity. Others 

* For a full and interesting account of the early history of the in- 
duction coil, see Fleming, "The Alternate Current Transformer." 
t See Fleming, op. cit. 


quickly followed, and the drawings of the period com- 
monly represent these coils as fitted with handles for 
patients to grasp, showing the general idea of the mode 
of employing them in therapeutics. By the introduction 
of the separate "secondary" coil, and of the automatic 
contact breaker, the induction coil acquired its modern 
form, and the researches of Duchenne into the different 
physiological effects of long and short coils was an 
application of the principles already foreshadowed 
clearly by Henry's experiments with long and short 
wire spirals. 

Since then the medical induction coil has undergone 
many modifications at the hands of ingenious instru- 
ment makers, but few of these modifications have been 
of much value, because the principles determining the 
physiological action of the coils have received but scant 

It is convenient to consider the phenomena of the 
induction coil as depending on the magnetic field of 
force (§ 26), which exists round a wire carrying a 
current. When such a wire is wound into a helix, 
this behaves as a magnet, and the magnetic lines of 
force of a straight helix are arranged precisely like 
those of a bar magnet (see fig. 4). If a bar of iron is 
inserted into the helix, the magnetic permeability of 
that portion of the magnetic circuit becomes increased, 
because iron conducts magnetism several hundred times 
better than air does, and consequently more lines of 
force will traverse the helix for the same strength of 
current in the wire, and the magnetism of the helix will 
be increased. The magnetic field set up in the helix at 
the moment of closing the battery current reacts upoa 
the wire and produces in it a wave of opposing electro- 
motive force which retards the growth of the current sa 


that it does not instantaneously reach its full strength, 
and the collapse of the magnetic field at the moment 
of breaking the current also sets up a wave of electro- 
motive force in the wire which strengthens the battery 
current and shows itself by a bright spark at the place 
where the circuit is broken. 

In its simplest form the induction coil consists of a 
■coil of insulated wire wound upon a reel or bobbin with 
-an arrangement, usually a vibrating spring, for auto- 
matically closing and opening the circuit. When a 
current passes through it the spring comes into play, 
and the current is periodically established and inter- 
rupted, and so the magnetic field of the apparatus is 
caused to vary with every make and break of contact, 
and induction currents are produced in the wire coil. 
The induced current at break can be led off by properly 
arranged conductors and is known as the primary 
current, or the extra current ; the other does not leave 
the apparatus but expends itself in the closed circuit 
formed by the coil and the contact breaker. The 
primary current is therefore a series of impulses or 
waves, all passing in the same direction, and corres- 
ponding in time and frequency to the interruptions of 
the contact breaker ; each wave is due to a sudden rise 
of electromotive force in the wire, followed by a more 
-gradual fall, the whole time of each wave being a very 
small fraction of a second, and varying considerably in 
•diiferent coils. 

The secondary current of an induction coil, as its 
name suggests, is derived from another entirely inde- 
pendent coil wound upon the same bobbin as the 
primary coil. Being in the same magnetic field as the 
primary coil it is acted upon in the same way, but the 
effects produced in it are not quite the same, because 



they are quite free from the battery current which flows 
in the primary coil. In the secondary coil there is an 
induced electromotive force corresponding to the rise of 
magnetism and an opposite electromotive force corres- 
ponding to its fall. Both of these give rise to currents 
through an external circuit, and because they are in 
•opposite directions the currents from the secondary coil 
are said to be alternating. They are not exactly alike 
in all respects, although the total flux of electricity is 
the same in each, for the electromotive force at the 
break of the primary current is higher, and the duration 
•of the wave is shorter, than at the make, because, as 
iias been seen, the rise of the magnetising current in the 
apparatus is more gradual than its fall. 

Fig. 30. — Arrangement of wires in an induction coil. 

The electromotive forces developed by induction in 
the primary and secondary coils vary very much in 
•different instruments. In both coils the electromotive 
forces reach maxima which are higher than that of the 
l^attery which supplies energy to the apparatus. 

Fig. 30 is a plan of the arrangement of the wires in 
an induction coil, and fig. 31 shows an actual coil. 



The lettering is the same in both of the figures. One 
pole of the battery is connected to the binding screw A. 
The current then passes by the adjusting screw B, the 
vibrator H, and the support K to the horseshoe mag- 
net D. After traversing this the circuit gives off a 
branch to the binding screw P, and is continued to the 
primary coil EE, the return wire from which again gives 
off a branch to the second binding screw at P, and is- 
then continued to the other pole of the battery. The 

Fig. 31.— Induction Coil. 

two binding screws at P are thus in connexion with the 
two ends of the primary coil, and by means of electrodes 
attached to them the patient may be treated with the 
primary current of this coil. The secondary coil F is 
wound on a separate hollow bobbin and has its term- 
inals at S. This bobbin is made to slide like a sledge- 
on guides so that it can be made to approach or recede 
from the primary coil. At G a handle is seen attached 


to the iron core which can slide in and out of the pri- 
mary coilj and so further regulate the induced electro- 
motive force set up in both the primary and secondary 
•coils, by varying the strength of their magnetic field. 

Another and somewhat neater form of sledge coil is 
shown in iig. 32. The general plan of construction is 

Fig. 32. — Induction coil. 

the same as in the last figure, with the addition of 
divided scales by which the relative positions of 
primary, secondary, and core can be recorded and 
results verified. It must be borne in mind that the 
readings of the scale are not at all in proportion to the 
electromotive force or the current induced in the coils, 
they merely make it easy to reproduce a given condition 
at will. 

The mode of action of the automatic vibrator or 
contact breaker is clearly shown in the figures. The 
electro-magnet, by drawing down the spring H, breaks 
the circuit at the point of the screw B, whereupon the 
attraction of the electro-magnet ceases and the spring is 
released, and flying up re-establishes the circuit ; the 
action is then repeated, and the spring is kept in con- 
stant movement. By turning the screw B, the pressure 
upon the spring and its rate of vibration can be modi- 
fied. Instead of the separate electro-magnet it is easy 


to utilise the magnetism of the iron core for working the 
contact breaker, and this is done in those patterns of 
medical coil which have a fixed core ; but in these coils 
some mode of regulation other than that of a sliding 
core is required. 

In order that the coil may be used for medical pur- 
poses there must be some method of regulating its 
strength. The following methods are in actual use in 
medical coils : — 

1. By the use of a sHding core to vary the strength 
of magnetic field in the coils. 

2. By the use of a metal tube to slide over the core 
and so shield the coils from its action. 

3. By the use of a secondary coil (sledge coil) which 
can be brought into stronger or weaker parts of the 
magnetic field. 

4. By a switch for progressively taking up into the 
circuit greater or lesser portions of the coils. 

The variety of coils in the market is very great, and 
they can be had either separate or fitted up in a box 
with a battery to drive them, and with a drawer to hold 
wires and electrodes ; this is convenient, as it makes 
them more portable. An inspection of an instrument 
maker's illustrated catalogue, or better still of his stock, 
is the quickest way of becoming familiar with the types 
of coil in general use. 

In choosing an induction coil the points to be attended 
to are as follows : — 

First, to see that the vibrator works smoothly and 
evenly ; this is very important, as many coils are defec- 
tive in this respect, and give an irregular series of 
shocks of unequal strength, which is unpleasant for the 
patient ; before buying a coil it is a good plan to have 
it set in action, and to test it upon one's self. In this 


way it is easy to learn whether it works evenly ; and^ 
secondly, whether it permits of satisfactory regulation 
of its strength ; thirdly, the coil should be quiet in 
action ; fourthly, it should not require a large current, 
or else the cell used to drive it will require frequent 

The induction coil is most commonly used to excite 
muscular contraction, either for purposes of testing or 
for treatment, but it is also used for its action upon 
sensory nerves. In the first case a low electromotive 
force is best, but for the latter a high electromotive 
force is needed, and in the best instruments two 
separate and interchangeable secondary coils are pro- 
vided, one of a smaller number of turns of wire, and one 
of a very large number of turns, then either coil can be 
used as the case under treatment requires. Duchenne 
showed- that the physiological effect of a coil of fine 
wire with many turns, differed from that of a short coil 
of few turns and thick wire, and his observations on 
this point may be expressed in modern language as 
follows : — With a short coil of two or three hundred 
turns, the electromotive force is low, but it is sufficiently 
high to excite contractions in the muscles if the skin be 
properly moistened. A long coil of many turns, two or 
three thousand, gives a high electromotive force, and 
when applied to the surface of the dry skin, with dry 
electrodes, it acts powerfully in spite of the great resist- 
ance offered by this mode of application. It is therefore 
useful in cases in which the short coil will not act. 

On the other hand, the long coil is less useful for 
stimulating deep seated muscles, because it has a high 
resistance and a still higher impedance, which behaves 
as an enormous additional resistance, and therefore its 
available electromotive force may be several hundred 


volts when the external resistance is very high, and yet 
may be comparatively low through a resistance like that 
of the well moistened skin. This may be compared to 
the behaviour of a galvanic cell of high internal resist- 
ance, whose available voltage for a circuit of low 
resistance may be only a small fraction of its electro- 
motive force on open circuit (see § 45). 

A particular secondary coil was tested by means of 
an electrostatic voltmeter, and the potential difference 
at its terminals came out at 89 volts. With a non- 
inductive external resistance of 1000 ohms, in shunt to 
the voltmeter, the potential difference fell to ten volts. 

Another way of expressing the difference between 
long and short coils is to say that the short coil gives a 
lower voltage but a larger current, while the long coil 
gives a high voltage and only a very small current ; the 
large current is able to influence deep muscles because 
it is not so much dissipated by diffusion through the 
tissues as is the case with the small current. And, on 
the other hand, the small current of the fine coil makes 
itself sharply felt at the point of entry through the skin, 
but is scattered by diffusion through the underlying 
tissues, and there is not sufficient density of current in 
the muscles to affect them. The fine coil should be 
used with a wire brush electrode, or other electrode of 
small surface, as this concentrates the current at the 
points of contact, and produces effective stimulation 
there, with little or no effect upon parts which are 
further removed. 

Most of the coils in common use have intermediate 
properties, because the number of their windings is 
neither very small nor very great, and they are there- 
fore not so well suited for the special purpose of stimu- 
lating the sensory nerves of the skin or the mucous 


membranes, without affecting the deeper parts at the 
same time. Duchenne has maintained that for the 
treatment of neuralgic pains the use of a current from a 
short coil is injurious, because it produces muscular 
contraction, and affects the deep structures, whereas 
the action should be limited to the surface, and patients 
will usually say that the pain is increased by the treat- 
ment if a short coil is used. 

73. Long and short secondary coils. Thick 
wire and thin wire coils.— The difference between 
a short coil of thick wire and a long coil of fine wire, 
depends very much more on the number of turns than 
on the diameter of the wire, for the ohmic resistance 
of the wire is only a small part of the total impedance 
of the coil. One secondary coil can therefore be made 
to take the place of two or more separate coils, if by 
any means the number of turns in actual use can be 
varied. This may be done by tapping the secondary 
coil in several places, and bringing out a wire from 
each place tapped to a separate binding screw. Coils 
of this kind can be had, in which one-third or two- 
thirds, or the whole number of the turns, can be used 
at will. 

It is difficult to specify precisely what is the most 
suitable number of turns to give the short coil or long 
coil effects. In Duchenne's instruments the short coil 
seems to have had about 500 turns, and the long coil 
about 4,000, but this is only a guess, as he merely states 
the lengths of wire used. But the number of turns is 
not the only factor concerned, and these figures will 
suffice to indicate the general proportion between the 
two coils. 

74. Frequency of interruptions. — The interesting 
results obtained from currents of very high frequency 



of alternation, which have been so ably developed by 
Elihu Thomson, Tesla, D'Arsonval, and others, has 
turned the attention of medical men to the study of the 
contact-breaker of the induction coil, and coils can now 
be bought with regulating devices to produce at will 
almost any rate within comparatively wide limits, as, 
for example, from one vibration to two hundred per 
second in Ewald's coil (fig. 33). In this the vibrator 

Fig. 33. — Ewald's coil. 

has the form of a pendulum C, swinging between two 
springs B and D. B can be altered in position by 
means of the screw A, and so controls the range of 
swing of the pendulum. Other coils again are fitted 
with a break, " the singing rheotome," which vibrates 
so rapidly as to emit a high pitched note, estimated at 
500 per second. None of these rapid breaks, however, 
really attain to the conditions of true high frequency, 
which can be obtained with Leyden jar discharges, for 
these may have a period of oscillation equal to hundreds 


of thousands or even millions per second, a rate which 
is a thousand times more rapid than that of the most 
rapid mechanical contact-breaker. 

The average rate of vibration of the contact-breaker 
in common use in medical coils is about fifty per second. 

Much work remains to be done before our knowledge 
of the influence of varying frequency of vibration can be 
considered satisfactory. It is very probable that the 
sensory nerves respond differently to vibrations of dif- 
ferent frequencies. For instance, the heat vibrations 
emitted by warm bodies, and felt as a sensation of 
warmth, are at a rate of billions per second, but yet 
can easily be distinguished by the nerve endings from 
other forms of tactile sensation. 

If the impulses are so infrequent that the muscle has 
time to relax between its successive contractions there 
is more" commotion of the muscle, and greater dis- 
comfort than when it is maintained in a condition of 
tetanus ; to produce this requires about 20 impulses 
per second. 

The decreased effect of a coil whose contact-breaker 
is vibrating rapidly, is mainly due to the fact that the 
exciting current has not time to rise to its full value 
before it is broken again, consequently the magnetisa- 
tion of the core, and the induction in the secondary coil 
do not rise so high as they would if the same coil were 
worked at a lower speed. 

Duchenne preferred a rapid vibrator for acting upon 
sensory nerves, and for certain conditions of muscular 
atrophy and for stimulating muscles when they would 
not respond to slow interruptions, or had lost the 
muscular sense ; for general purposes of muscular 
stimulation he advises slow interruptions, and prefers 
them in treating muscles paralysed by cerebral lesions, 



because the slow stimuli acting less upon sensory nerves 
are less likely to set up reflex irritation at the seat of 
lesion in the skull. He believed that rapid vibrations 
might hasten the degeneration of muscle in certain 
cases. His slow vibrations were sometimes of the rate 
of one or two per second. 

From 40 to 60 vibrations per second is a very suitable 
rate for testing and treating muscles ; at higher speeds 
a peculiar benumbing efl"ect makes itself felt when the 
electrode is applied over a sensory or mixed nerve 
trunk ; this numbness is felt over the area of distribu- 
tion of the nerve, and with it a strong but not painful 
vibration is felt all along that part of the nerve trunk 
which extends from the point stimulated to the peri- 
phery. It does not extend upwards along the nerve trunk, 
but is referred to its distal parts, very much as is the 
case with the ulnar nerve when it is struck or pressed 
at the internal condyle of the humerus, and produces 
pain or tingling in the ulnar side of the hand and 

Much has been made lately of the important differ- 
ences in effects which depend upon the rate of the 
contact breaker, and the number and fineness of the 
coils of wire. In gynaecology especially the long coils 
and the fine wire are insisted on. In the United States, 
now-a-days, very highly finished coils are made and 
sold, some being fitted with very elaborate contact 
breaking arrangements driven by electromotors. 

75. Measurement of induction currents. — The 
measurement of the electromotive force and current due 
to induction in the primary coil is complicated by the 
presence in the same circuit of the battery which drives 
the coil, and which exerts its own proper action upon 
any measuring instrument which may be put into the 


circuit. The secondary coil, however, is an inde- 
pendent coil and the effects of induction in it can be 
measured, but not by an ordinary galvanometer, for if 
the experiment be made it will be found that connecting 
a secondary coil to a galvanometer produces little or no 
effect upon the needle. The alternate impulses from 
the coil tend to deflect the needle first in one direction 
and then in the other, with the result that the needle 
either remains quite still or else oscillates about its 
position of rest. If the magnetic needle be replaced by 
a small bundle of fine soft iron wires, these will be- 
attracted by the coils of the instrument quite indepen- 
dently of the direction of the current in the coils, and 
in spite of the rapid changes of direction of the currents 
of a secondary coil, steady deflections of such a soft 
iron needle are obtained. 

Mr. Giltay of Delft, Holland, has made an instru- 
ment'" for use with medical coils. It depends in prin- 
ciple upon the attraction of a soft iron needle, which is 
suspended between two coils in a position at an angle 
of 45 degrees with their axis. When a current traverses 
the coils, the needle tends to set itself in the axis of the 
coils, and its movements are made visible by means of 
a scale and pointer, or else by a small mirror, as in 
Thomson's reflecting galvanometer. 

The electromotive force of an induction coil can be 
best measured by an instrument invented by Lord 
Kelvin, and known as an electrostatic voltmeter. It 
is based upon the mutual attraction of two bodies op- 
positely electrified, and has the advantage of using no 
current, and therefore it measures the electromotive 
force of the coil on open circuit, but the capacity of the 

* " Ann. der Physik und Chemie," Bd. 50, Leipzig, 1893 (figure). 


voltmeter exercises a lowering effect upon the readings. 
When the circuit of an induction coil is closed the 
voltage at its terminals falls away rapidly, particularly 
if it be closed through a low resistance. 

Reference has already been made to a coil which 
indicated a mean electromotive force of 89 volts on 
open circuit, falling to 10 volts when its poles were 
joined through a conductor with a resistance of 1000 
ohms. This observation shows the importance of 
measuring the electromotive force of a medical coil 
under conditions resembling those under which it is 
to be used. 

The methods of measurement just indicated give 
readings of the mean currents or electromotive forces, 
and it is not always sufficient to know this, for the 
effects desired may be proportional, not to the mean 
current, but to the maximal current, or to the sudden- 
ness of its rise or fall. This is important in medical 
work ; for the physiological effect in giving a shock 
" appears to depend in great part upon the suddenness 
with which the maximum current strength is reached. 
Of two discharges which reached equal maxima, that 
which arrived at it in the shortest time would be the 
most effective in producing shocks. The value of the 
maximum current strength is also important."* 

It follows, therefore, that it is not enough to know 
merely the mean current or mean electromotive force of 
a coil, unless the maxima can also be arrived at. 
When the shape of the curve of the current (see next 
paragraph) is regular, the maxima can be calculated 
from the observed magnitudes of the mean current, but 

* Fleming, " The Alternate Current Transformer," vol. i., p. 180, 
London, 1892. 


if the shape of the curve is irregular, then readings of 
the mean current or mean electromotive force are not a 
sufficient indication of the physiological effects of the 
currents. Giltay's instrument has, therefore, no great 
value for the irregular currents of a coil. 

76. Graphic representation of currents. — The 
changes in value of any varying quantity, as for 
example, electromotive force or current, can be repre- 
sented graphically by a curved line, just as the varia- 
tions in the body temperature of a patient are recorded 
upon the temperature charts used in clinical work. 

If a horizontal line be drawn to represent periods of 
time, and if magnitudes of electromotive force be repre- 
sented by distances above the base line (positive) or 
below it (negative) then an electromotive force gradually 
rising from zero to a maximum of fifteen volts positive, 
and falling again could be represented by the curved 
line ABC, fig. 34, and the continuation of the curve 
CDE, represents a reversal in sign of the electromotive 
force, and a fall to fifteen volts negative, followed by 
a. return to zero, the period of time of the whole cycle 
being represented by the base Hne AE. Similar curves 
could clearly be drawn to represent any values of a 
varying electromotive force or current and any periods 
of time. 

When the shape of the curve is known the electro- 
motive force at any instant can be readily determined 
by plotting out the curve, upon paper suitably ruled 
with lines (squared paper), and conversely curves can 
be constructed by observing a sufficient number of in- 
stantaneous values and marking them out on the paper 
and drawing a line to connect them. 

The curve (fig. 34) represents the gradual rise and 
fall of the electromotive force from a properly con- 



structed alternate current dynamo machine, and may 
be taken as approximating very closely to the shape of 
curve of an alternating system of electric light supply, 
and with such a curve the ratio of maximum current to 
mean current is as i to "637, or as 1*57 to i, if the mean 
be taken as unity. A curve of this kind is known as a 
simple periodic curve, or a sine curve, and the current 
from an alternating current dynamo is often spoken of 
as a sinusoidal current. Owing to the gradual ascent 

•V Volts 

Fig. 34. — Graphic representation of a steadily varying electromotive force. 

and descent of the wave, the physiological effects are 
somewhat different to those of currents which rise and 
fall more abruptly. Of late the physiological and thera- 
peutic effects of sinusoidal currents have been studied 
particularly by M. D'Arsonval and MM. Gautier and 
Larat," and they will be dealt with in a later para- 

Although the shape of the curve of the medical in- 

* See " Revue internationale d'electrotherapie," 1892-93, vols. iii. 
and iv. ; "Archives d'electricite medicale, 1893-94, vol. i. 



duction coil is not fully understood, still we are not 
without some information upon the subject. Many 
curves, most of them wrong, have been drawn from 
time to time on theoretical grounds to represent them, 
but actual tracings have also been taken, one or two of 
which are reproduced here from a paper by Dr. Kellogg'" 
in which the method of doing so by means of an instru- 
ment devised by d'Arsonval is fully described. 

Fig. 35 shows the discharge curves of a secondary 
coil when the battery current was made and broken 

Fip. 35. — Secondary coil discharge. Battery current made and broken by hand 
A. Wave at make. B. At break (Dr. Kellogg). 

slowly by hand. Here the wave at make is completed 
before the reverse current of break commences ; the 
wave has a gradual and uniform contour both at the 
make and break and a pause is seen between them. 
Fig. 36 shows a tracing taking with the vibrating 

Fig. 36. — Secondary coil. Vibrator in action (Dr. Kellogg). 

* "The International System of Electrotherapeutics," edited by 
Dr. Bigelow (F. A. Davis & Co., Philadelphia), 1894. 


contact breaker in action, the make discharge com- 
mences as before, but the break discharge following too 
quickly after it, has altered the contour of the tracing, 
which now shows the break discharge as starting from 
the top of the wave of the make discharge, instead of 
from the line of zero potential. This means a reversal 
more or less abrupt of the direction of the current, and 
a greater sensation of shock. 

Fig. 37, from a paper by Dr. Lewis Jones, "^ on the 

Fig. 37.—" Make " discharges (short lines) and " break " discharges (long lines) of 
a coil (to be read from left to right). 

duration of the discharges of the induction coil, also 
shows, in another way, the abrupt passage from the 
make to the break before the completion of the former 
of the two discharges. 

The extent of the interference of the two waves of 
current depends upon the character of the contact 
breaker, and varies in different coils, the more rigid the 
spring, the more likely it is that the rebound or break 
will follow too quickly upon the make. The shocks of 
an induction coil can often be very considerably altered 
in character by a little adjustment of the contact screw, 
because changes in its position may alter the play of 
the spring and so make a difference in the way in which 
it rebounds after contact. 

77. Practical conclusions. — The induction coil 
has been considered at some length in the preceding 
paragraphs because it is perhaps the most important 

* " Electrician," London, July 21st, 1893. 


electrical appliance in common medical use, and be- 
cause the points which have been discussed are of value 
as a guide in the choice and in the use of the instru- 
ment. Taking everything into consideration, the induc- 
tion coil to be preferred for medical use should be of the 
sledge pattern, its contact breaker should work easily 
an evenly, its spring should not be too rigid, its rate 
should be capable of variation, and its discharge curve 
should approximate to that of a sinusoidal wave, each 
discharge being given time to terminate before the com- 
mencement of the next succeeding one. There may be 
two different secondary coils, or else one which is 
tapped at several places, so that either a part or the 
whole of the turns may be utilised at will. With a 
greater number of turns the rise and fall of the current 
is more gradual than with a smaller number, and the 
painfuleffect or shock is lessened thereby.* 

When muscle is to be stimulated through the mois- 
tened skin a lower electromotive force, a smaller 
number of turns and a slower rate of contact breaker 
may be used. When cutaneous sensory effects are 
desired, a large number of turns, a higher electromotive 
force, a rapid rate of vibration, and a dry skin, are to 
be preferred. The very rapid vibrator or singing rheo- 
tome has its chief use in producing a local anaesthesia 
in the part to which it is applied. For applications to 
mucous membranes the short coil is likely to prove 
more painful than the long coil, unless used carefully, 
because the mucous membrane with its low resistance 
may allow a large current to pass even from a coil 
whose electromotive force is not high. When the long 

* Messrs. Waite and Bartlett, 18 Pall Mall East, supply a well 
made American coil with two vibrators, one slow and one rapid, 
which is a good instrument. 


coil is used its own high self-induction will tend to pro- 
tect the patient, so that the actual electromotive force 
applied to the body will be far below the electromotive 
force of the apparatus, as measured upon open circuit. 
The effects of the primary coil approximate very nearly 
to those of a short wire secondary. It has already been 
stated that the primary current is unidirectional, not 
alternating ; it is probable that its discharge curve is 
more abrupt and peaked, and of shorter duration than 
that of the secondary coil, and this difference will be 
the more marked if the primary consist only of a com- 
paratively few turns. 

There is at present no definite evidence to show that 
there are any important physiological or therapeutical 
properties possessed by the primary current, and not 
possessed by a suitably wound secondary coil. 

78. Accessory apparatus. — Conducting wires. — 
The conductors or leads by which the current is con- 
veyed from the battery or other generator to the place 
where it is to be used, should be of insulated flexible 
copper wire. Copper is used because it is the best 
conductor among metals with the exception of silver, 
which indeed is not very much better and is out of the 
question on account of its cost. It is best to use 
insulated wire to avoid any risk of shocks or short 
circuiting from the wires coming into accidental contact 
with one another. Suitable wires may be bought 
insulated either with cotton or silk or india-rubber, and 
for cases where the current has to be conveyed some 
little distance it may be convenient to use double con- 
ductors made of two insulated wires twisted together. 
In this case it is well to mark the ends, so that there 
may be no difficulty in recognizing the positive and 
negative wires. A pole-tester, § 62, will prove useful 


for this purpose. It is useful to have the two con- 
ductors covered in two different colours, say red and 
green, as it makes it more easy to distinguish between 
them, in tracing their attachments to the battery or to 
the electrodes. A convenient length is four and a half 
or five feet. Suitable cords with ends to fit the battery 
terminals are sold by the instrument makers. It is 
important to know that the wire core of these covered 
cords may become broken inside the covering, and give 
trouble if not discovered, the commonest breaking 
point being near the ends. Faulty connections are one 
of the commonest causes tending to throw electrical 
apparatus apparently out of gear, and although it is not 
hard to detect the fault by careful examination, yet 
only too often much difficulty is found, and in con- 
sequence the battery is condemned, or the services of 
the instrument maker are called in. It need not be 
said that this is the wrong way of doing things, for 
everyone using a battery should make himself familiar 
with the proper management of it, in order to avoid 
_the expense and annoyance of perpetually putting it 
into the hands of an instrument maker. 

As a matter of fact with moderate care no difficulty 
need occur from faulty contacts. It is advisable for the 
sake of neatness, to use but one form of binding screw 
as far as possible. There are of course many forms in 
constant use, and a few minutes may be well spent in 
inspecting an electrical instrument maker's stock. 

79. Electrodes. — The terminals by which the cur- 
rent is applied to the place where it is to be used are 
called electrodes. The word electrode is also used to 
describe the terminals by which the current leaves the 
battery or enters any instrument. The special ter- 
minals used in medical treatment are sometimes called 


rheophores, a term which has also been apphed to the 
conducting wires, and here we may once for all protest 
against the use of so many unnecessary terms. Such 
words as rheophores for electrodes or conducting wires, 
rheostats or rheochords for resistances or resistance 
coils, rheotropes for commutators, and rheotomes for 
contact breakers, are, as a rule, not wanted, and the 
words in common use among electricians are enough for 
all medical purposes. The variety in nature and shape 
of the electrodes used in medical practice is immense ; 
it is necessary, however, to describe some of them. 
The old-fashioned brass handles and wet sponges are 
now almost wholly abandoned, and the favourite form 
of electrode at present is a disc of metal screwed into a 
handle and covered over with wash-leather. 

The handles are of varied design, some being fitted 
with keys for closing the current or for opening it, or 
even for reversing it, one or two of these handles are 
figured here, and many more will be found in the in- 
strument makers' catalogues. One handle with a key 
for closing the circuit is useful for the testing of muscles. 

Fig. 38. — Handle for electrode, with key. 

Care must be exercised to keep the electrodes clean, 
and on this account metal is better than carbon ; the 
amadou, or flannel, or wash-leather covers, should be 
often renewed, and as far as possible a separate set 
should be kept for each patient. 

Several sizes are required. Professor Erb has sug- 
gested the adoption of electrodes of standard sizes 
because the density of the current and the effective 



resistance of the surface at the point of entry depends 
upon the size of the electrode, that is to say, the area 
from which the current passes to the patient. For 
different effects one may desire at one time a current 
diffused over a large surface of entry, and at another a 
current concentrated at a small surface. In the opera- 
tion for the removal of superfluous hairs by electrolysis^ 
the indifferent electrode is large and the local effects on. 
that part of the skin which it touches are imperceptible, 
but the active electrode is a fine needle, and the density 
of the current at its point is such that strong local 
effects are produced where it pierces the skin even 
when the current is only two or three milliamperes. 
By using standard sizes one can more readily convey 
to others a correct idea of the current density used 
in any particular case. Erb's standard sizes are the 
following : — 



ter of disc. 

Area of 



•5 cm. 
1-3 M 

'2 in. 
•6 „ 

•25 sq. cm. 

•04 sq. in, 

•28 , 



2 ,, 

3-5 M 

•8 „ 
1-4 n 


1-5 > 



2 ,, 


3 . 

Very large 

7-6 „ 

TI-2 ,, 


4'4 n 



7-6 , 


13-3 » 

5-25 ,> 



These sizes do not cover all the variations which are 
required for medical practice, for in Apostoli's treat- 
ment of uterine disease the indifferent electrode is 
larger still, while, for nsevi and epilation, electrodes 
made of fine sharp needles are used. An obvious 
objection to this series of sizes is that they are not 
very regular in scale, and that for the important size 


of " small " electrode two alternatives are proposed. 
Moreover, the numbers are difficult to remember ; it 
would be quite as useful and more convenient to adopt 
a series of circular electrodes numbered according to 
their diameters in centimetres from i to lo. Still 
another size is proposed by the same author (Erb) for 
use in testing the contractility of muscles, namely one 
■of 4 cm. diameter. 

For practical purposes of diagnosis and treatment it 
-will generally suffice to have three or four sizes of disc 
electrode, the smallest of half an inch or one centimetre 
in diameter, the largest of three inches. A roller elec- 
trode and a fine wire brush are also necessary at times. 

Fig. 39. — Electrodes. 

A very good form of disc electrode is made, in which 
the operation of renewing the wash leather covering can 
be quickly carried out without needle and thread. The 
electrode is made of two cupped discs of metal, which 
screw together, and so hold the edges of the wash 
leather firmly fixed between them (see fig. 39). 

The more special forms of electrode will be described 
and figured in the chapters which deal with the par- 
ticular operations in which they are used. 



In some medical applications both the poles of the 
battery are used equally, and in that case the electrodes 
at the two poles may be similar, but more often the cur- 
rent is applied to the affected part with one pole, which 
is then known as the " active electrode," and may be 
positive or negative according to the treatment required, 
the circuit being completed by the application of the 

Fig. 40. — Tin electrode and sheath. 

other electrode, the '' indifferent electrode," to any 
convenient part of the body ; under these circumstances 
the active electrode may require a handle for its proper 
manipulation, while the indifferent electrode is most 
conveniently arranged as a simple metal plate, which 
can be applied to the surface of the body and left there 


during the treatment. It is generally an oval plate of 
pure tin or pewter four or five inches long. It is light 
and sufficiently flexible, and can be bent to fit the sur- 
face of the body. Plates of lead are not so good, nor so 
convenient. On one side is a binding screw for the 
attachment of the battery wire, and the other side is 
covered with a smooth piece of amadou or w^ash leather, 
which can be moistened with warm water before use. 
There should be a sheath or pocket with one side water- 
proof, to contain the electrode (fig. 40), this will serve 
to protect the patient's clothes from being whetted with- 
out interfering with the passage of the current. Bare 
metal must never be applied directly to the skin unless 
electrolytic effects are wished for, the current is very 
much more painful when it enters the skin from a 
metallic surface that when it first passes through a 
layer of moist badly conducting material. The reason 
for this is that the latter gives a more even contact, and 
most of the electrolytic action takes place in the thick- 
ness of the wet flannel or wash leather instead of in the 

The indifferent electrode may be slipped between the 
clothing and the skin, the pressure of the clothes will 
then suffice to keep it in place, or if the patient is lying 
down the electrode may be put underneath the shoulders 
or the hips, or it may be held against the body by 
the patient himself or by an attendant. In either case 
the operator is able to give his whole attention to the 
other or active electrode. Care must be taken to see 
that the contact of the indifferent electrode with the 
skin is well maintained, and that no dry clothing lies 
between. Sometimes, especially with children, it may 
be fastened on by a few turns of a bandage, or by a soft 
garter or belt of some kind. Electrodes to buckle or 


clasp upon a limb are figured in the catalogues and are 
useful. The precaution should be taken of seeing that 
the proper side of the sheath and the proper face of 
the electrode are together, for the waterproof side will 
not conduct. 

80. Current collectors.— Medical batteries for gal- 
vanic treatment are made up of a large number of cells 
(20, 30 or 40 arranged in series), but the number of 
cells to be used in different cases varies very much. 
On this account a quick and simple plan of altering the 
number of the cells included in the circuit is required so 

Fig. 41. — Plan of a single current collector, 

that the curren. may be readily increased or diminished 
to suit the needs of each case by switching cells in or 
out of circuit. The plan is as follows : — 

In the diagram, fig. 41, six cells are shown numbered 
I to VI, they are joined in series, and from their ter- 
minals wires are led off to seven corresponding studs 
numbered o to 6. It may be seen that a movable 
metallic arm springing on to stud No. i will throw one 
cell into circuit between the binding screws marked + 
and — , and similarly when the arm is placed on any 



other stud it brings into the circuit the number of cells 
shown by the figure marked against the stud. 

This is in brief the principle of the current collector, 
as applied to medical batteries, the stud marked o being 
connected with one pole, say the positive pole of cell 
No. I, and leading to a binding screw marked +, stud 
No. I being attached to the negative pole of the same 
cell and when the movable arm touches stud No. i, the 
current passes along it and from there goes to the other 
binding screw of the battery marked as shown in the 
figure. Cell No. I. only is then included in the circuit ; 
if the pointer be transferred to another stud, numbered 
let us say 6, then six cells are in circuit and are being 

A more complicated current collector has been de- 
vised, by means of which the current may be taken 
from any cell or any group of cells commencing at any 
point, the advantage being that the cells can be used 
equally. In the single collector the first cells are 
always drawn upon, and are likely to run down before 
the last cells, which are only needed occasionally. 
With the double collector if six cells are required not 
only could cells i to 6 be chosen but cells 4 to 9, or 7 to 
12, or 13 to 18, or any other set of six. With the single 
collector the first cells must always provide current and 
cell No. 12 can only be used when eleven cells are insuf- 
ficient. Accordingly, with a single collector, the last 
cells of the series are very seldom called on at all, while 
the first cells have to do duty every time the battery is 
used. Another advantage of the double collector is that 
with its aid the working of every cell of the battery can 
be separately tested ; the double collector, however, is 
rather more expensive. If in the figure of the single 
collector (fig. 41) the wire leading from cell No. i to 



the stud numbered o were not continued to the positive 
terminal of the battery, and if this latter were connected 
instead to a second arm, pivoted on the same axle, but 
electrically insulated from the first one and capable of 
independent movement (fig. 42), it can be seen that 
with the two arms on the studs 3 and 6 the current 
would be taken from cells 4, 5, and 6 only, that is to 
say the group of cells 4 to 6 would supply the current to 
the circuit. In like manner any number of consecutive 

Fig. 42. — Double collector. 

cells from one upwards could be picked out from any 
part of the whole series. It is usual for one of the arms 
to carry a circle so divided and numbered as to read off 
directly the number of cells in use (fig. 42). 

The studs of current collectors must be of good size, 
and the pointer just broad enough to touch two at once, 
that the number of cells in the circuit may be increased 
or diminished without breaks of current and unpleasant 
shocks at the moment when the pointer moves from one 
stud to the next. At the same time care must be taken 


that the movable pointer of any collector is not left for 
any length of time in contact with two studs at once, 
for when it is in that position one cell is short-circuited 
and its energy is being ruinously wasted/" 

When it is wished to test the working of a medical 
battery, the poles must be joined through a high resis- 
tance, for example, any of those described in § 83. 
With about 1000 ohms the current is reduced to a 
magnitude suitable for measurement with the miUi- 
ampere meter ; failing this the electrodes should be 
placed in water, some little distance intervening be- 
tween them, and the pointer must then be gradually 
moved round the studs, the galvanometer being watched 
carefully. If the battery is in proper order it will 
indicate a regular rise of current step by step, for every 
cell added to the circuit. If the galvanometer needle 
falls to zero as the pointer is passing from one stud to 
the next, it indicates that the current is broken at that 
moment, and if a patient was in circuit he would receive 
an objectionable shock. If the needle falls to zero when 
the pointer is on a stud, it shows that the connection 
between that stud and the battery is faulty. 

It is a bad practice to try to test a battery by con- 
necting the terminals by a direct metalhc contact except 
through a coil of high resistance, 1000 ohms or so, 
otherwise the strength of current may be so great as to 
damage the galvanometer, and it will probably be too 
large even with one cell for a galvanometer graduated 
in milliamperes to give readings of it. If no resistance 
coil be at hand the plan of putting the electrodes into a 
little water in a saucer will usually suffice to reduce the 
current in the circuit to a quantity which can be mea- 

* This can be prevented by the use of a collector having a divided 
arm, with its two portions joined through a resistance (see fig. 18). 



sured in milliamperes. If the battery be not fitted with 
a galvanometer, one must be attached for this mode of 
testing. It may be connected to the terminals of the 
battery, in series with the resistance employed. 

81. Commutator or current reverser.— An appar- 
atus for reversing the direction of the current in the 
external portion of the circuit is indispensable for some 
medical purposes. It is difficult to make a satisfactory 
examination of the reactions of nerve and muscle with- 
out one. There are several forms in common use, but 

Fig. 43. — Commutator. 

one only will be described (fig. 43) ; it was devised by 

It consists of a cylinder of vulcanite M, having at 
each end a metal cap or ferrule C, D, and supported 
between two uprights in such a way as to revolve easily 
about an horizontal line, each end is connected to a 
binding screw A, B, and each metal cap is prolonged in 
the form of a cheek E, F, along one side of the vulcanite 
cylinder for two-thirds of its length. On either side of 
the cylinder springing against it, are two pieces of metal 
I, and L, connected with the terminals of the battery. 


When the cylinder is turned by means of the handle Z, 
either of the metal cheeks can be brought into contact 
with each of the springs I, L. The positive pole of the 
battery connected say with L, can thus be brought into 
connection with either the binding screw at A, or at B, 
so that the current can be made to pass in either direc- 
tion at will round the external portion of the circuit 
between A and B. The + and — signs on the vul- 
canite cylinder indicate the polarity of the binding 
screws ; in the position shown A is positive, a half 
revolution of the cylinder alters A to negative, and 
therefore the reverse side of the cylinder, which then 
comes into view, will have the -f and — signs trans- 
posed also. 

82. Regulation of current. — When the current is 
regulated by the method described in § 80, it will be 
seen that, neglecting the resistance of the battery, the 
electromotive force is the only thing altered in the 
circuit. But by Ohm's law we know that the current 
is numerically equal to the electromotive force divided 
by the resistance of the circuit, so that it might be 
regulated by introducing or removing resistances, the 
electromotive force being kept constant. In some cases 
it is more convenient to regulate by this method. As 
for example, in regulating the current from the electric 
light mains, where the electromotive force is maintained 
at a constant figure. In general, with batteries, when 
the total resistance of a circuit is large, it is more 
convenient to alter the electromotive force than the 
resistance in the circuit. Thus, suppose a circuit has 
a total resistance of 3000 ohms, and is acted on by 
twelve cells of 1-5 volts each, there will be a current of 
six milliamperes ; if now it is required to double the 
current it is easily done by adding twelve more cells. 


taking for granted that their internal resistance may be 
neglected, but if it were desired to make the alteration 
by reducing the resistance of the circuit it would be 
necessary in order to double the current, to take out a 
resistance of 1500 ohms, which might be impracticable. 
When it is desired to increase current by taking out 
resistances, it is of course requisite that the resistances 
to be removed must first be connected up in the circuit 
before the commencement of the operation. If the total 
resistance is small this can be done, and in such cases 
the current is most easily governed by variable resist- 
ances in the circuit. Thus, suppose a circuit made up 
of a cautery burner whose resistance with its leads 
amount to 'oi ohm, and an accumulator whose electro- 
motive force is two volts and internal resistance "002 
ohm ; the current would be well governed by having a 
variable resistance up to -5 ohm in the circuit. When 
the current was turned on with full resistance it would 
amount to about 3*9 amperes, and by reducing the 
variable resistance to -088 ohm a current of 20 amperes 
would be given which would probably suffice to heat 
the burner. 

83. Resistances. — Resistances or rheostats* are 
made up in many forms to suit the purposes for which 
they are required, and the currents they have to carry. 
Fig. 45 shows an arrangement of standard coils for 
measuring purposes, to form a " resistance box." The 
coils are generally made of a length of insulated 
German silver wire doubled on itself, fig. 44 (that 
the coils should have no self induction) and coiled 
on a bobbin. Coils are then arranged in the following 

* The word " rheostat" is perhaps the least objectionable of those 
referred to in § 79, solely, however, because ic has been hallowed 
by use. 



order: — i, 2, 2, 5, 10, 20, 20, 50, 100, 200, 200, 500, 
1000, 2000, 2000, 5000 ohms respectively, so that any of 
them can be thrown in or out of circuit by removing or 
replacing plugs on the top of the resistance box. It will 
be seen that with the above arrangement of coils any 

Fig. 44. — Plan of Resistance Coils. 

resistance from i to loooo ohms can be put into circuit* 
Such resistance boxes are capable of the very highest 
accuracy, but as a rule this is not required in medical 
work, and they are damaged if any large current is sent 
through them, besides which they are exceedingly 

Fig. 45. — Resistance Box. 

costly. They are necessary for scientific investigations, 
or where it may be necessary to find resistances of 
apparatus or the electromotive force of batteries with 
high accuracy. 

For medical treatment it is more important to have a 


resistance which can be smoothly adjusted and varied 
while the current is passing, than one which is gradu- 
ated exactly in ohms. 

An useful form of adjustable resistance is shown in 
fig. 46, where a movable arm is made to touch succes- 
sively upon a series of metal studs, the amount of 
resistance thereby interposed being shown by figures 
marked opposite the studs. 

A form of resistance coil that will frequently be 
found useful is one which is known as the " wire rheo- 
stat." It is very convenient in cases such as the 

Fig. 46.— Adjustable resistance for medical use. 

example given above, in which there is a small external 
resistance only in the circuit, and a large current is to 
be regulated. It usually consists of a long open cork- 
screw coil or helix of moderately thick uncovered 
German silver or other wire, such as platinum silver 
alloy, of high specific resistance. The current is led in 
at one end of the helix and a metal sliding piece which 
can pass from end to end of the coil forms the other 
terminal. The resistance interposed is easily seen to be 
proportional to the number of turns of the helix between 
the end attached to the terminal and the sliding piece 



The form of this resistance is favourable to cooHng, 
thus a much larger current may be driven through it 
than through a coil of covered wire not open to the air. 
It is especially useful for regulating the current in 
cautery or lamp instruments (see Chap. XV.). 

84. Water rheostat. — Another adjustable resistance 
apparatus made up in many forms is the "liquid 

Fig. 47.— Water rheostat. 

rheostat." It consists of a glass vessel, watertight 
and filled with water or some saline solution, it ter- 
minates below in a metal foot B and binding screw, 
and a metallic rod having a screw passes in from above 
through a collar A, and this carries the other binding 
screw. When the rod is screwed quite down it touches 
the base of the tube, and the circuit is completed 



through the metallic contact ; when it is raised the 
current must pass through the badly conducting liquid. 
The resistance offered by the liquid varies with the 
length of liquid to be traversed and the nature of the 
solution, and the rod can be roughly graduated for the 
resistance of the liquid to be used. In a modification 

Fig. 48. — Graphite rheostat. 

of this instrument a damp sponge takes the place of 
the liquid ; the resistance varies with the pressure upon 
the sponge, which is regulated by turning a screw as 

85. Graphite rheostat. — A very handy form of ad- 
justable rheostat for high resistances and small currents 


Fig. 49.— Plan of graphite rheostat. 

is a sliding graphite resistance, figs. 48 and 49. It 
consists of two parallel pencils of graphite, with a metal 
sliding piece moving between them, and in contact with 
both. As the position of the slide is altered, a greater 
or less length of the badly conducting graphite is 
brought in the circuit and the resistance of the circuit is 



varied thereby. Graphite rheostats are also made up 
in various patterns. 

It must be borne in mind that a resistance, suitable 
for regulating small currents, may be burnt and de- 
stroyed if large currents are allowed to traverse it, also 
that a resistance of one or two ohms may be ample for 
regulating a lamp or cautery, but will exercise no 
appreciable regulating effect upon a circuit of high 
resistance. In general a rheostat should have a resist- 

FiG. 50. — Vertical galvanometer. 

ance approximately equal to that of the circuit which it 
is to control. 

86. Galvanometers. — It is generally of the utmost 
importance that the medical man shall be able during 
the course of an electrical operation to see at a glance 
what current is passing, and for this purpose a galvano- 
meter is necessary. We may refer the student back to 
C5 27 for a cursory account of the theory of the galvano- 
meter. Here we have to describe one or two that are 
in common use. 



Galvanometers for medical use should always be 
calibrated and marked Dy the makers to read in milli- 

A galvanometer calibrated to read milliamperes may 
be called a " milliamperemeter just as one calibrated 
to read amperes is called an ammeter. Medical men 
owe it to Dr. De Watteville that the milliampere has 
been chosen to be the standard for medical purposes 
and for this it is a most convenient measure. 

Fig. 51. — Horizontal galvanometer with floating needle. 

Medical galvanometers may be conveniently divided 
into the vertical and horizontal forms. Fig. 50 shews 
one of the vertical type. They are easy to read, but 
after a time they cease to give correct readings and 
indicate too low a figure. They are convenient in use, 
however, because it is not necessary to set them in a 
definite position with regard to the north and south line 
(magnetic meridian) of the place where they are to be 

Fig. 51 shews a form of horizontal galvanometer 


which is very well suited for medical work. The needle 
floats in liquid, and therefore moves very readily. Its 
movements are "damped" by the liquid, which makes 
it nearly " dead beat," thus saving time, and there is no 
pivot to wear out. It can easily be disconnected, and 
so can be used with several different batteries. They 
are fitted either with one shunt or wdth tw^o, if large 
currents are to be used. 

Before use all horizontal galvanometers must be so 
placed and levelled, that the needle comes to rest at the 
zero, and swings freely about that point. The magnetic 
needle then points along the magnetic meridian of the 
place where it is to be used. 

Fig. 52 is a representation of Edelmann's large non- 
portable galvanometer which is very convenient as a 
standard instrument. At F is seen one of the three 
feet of the instrument with its levelling screw ; M is the 
base board, G a short cylinder of glass covered by a 
glass top, L which is perforated at the centre for the 
needle suspension to pass through ; these make a case 
for the instrument and keep it from dust. The magnet 
with its long straw pointer Z, the end of which is seen 
at W, is suspended by a cocoon silk fibre supported from 
a pin, which can be raised and lowered by a rack and 
pinion worked by the milled head S, N is a wooden ring 
which supports the pillar down which the suspension 
passes. T is the scale, a cylinder of paper divided to 
read in milliamperes. This arrangement of the scale 
is specially designed in order that the instruments may 
be read from a distance. At a and b are seen the wires 
which lead the current into and out of the galvano- 
meter, the three small discs numbered in the figure 
10, 20 and 30, should be numbered 10, 100, 1000, they 
are the heads of three screws by means of which shunts 



can be thrown in to reduce the proportion of current 
passing through the galvanometer to -^, ^J^ or ioW» 
respectively of that in the whole circuit, so that when 
one of these is in use the reading of the scale must 

Fig. 52. — Edelmann's galvanometer. 

be multiplied by 10, 100 or :ooo, as the case may be, 
to give the whole current in the circuit. In this way 
the instrument is enabled to give readings over a much 
wider range than would otherwise be possible. 

The arrangement of the shunt circuits is illustrated in 




figure 53. Between the binding screws marked + and 
— the galvanometer coils are represented. Two other 
paths are shown beneath, either of which can be com- 
pleted at the points of their respective screws ; both of 
them have a lower resistance than the circuit of the 
galvanometer coils and when closed they convey nine- 
tenths and ninety-nine hundredths respectively of the 
current, while the remaining tenth part or hundredth 
part traverses the galvanometer coils and produces its 
proper deflection. But if the deflection is known to be 


Fig. 53. —Plan of shunt circuits of a galvanometer. 

due to one-tenth of the current only, then to get the 
total current the indicated reading must be multiplied 
by ten, and the same for the other or 100 times shunt. 

Both shunt circuits are not to be closed at one time. 

By means of a battery and a resistance box it is easy 
to verify the readings of a galvanometer and to deter- 
mine whether the shunts work properly and correctly. 

In another form of galvanometer, sometimes known 
as the D'Arsonval type, the movements of the needle 
are controlled by placing it in a strong magnetic field 


between the poles of a horse-shoe magnet ; this has the 
effect of making the movement of the needle very "dead 
beat," that is to say it takes up its position without 
oscillating to and fro, and so when current is being 
measured time is saved ; on this account they are much 
in favour for certain purposes, but it is necessary to 
recalibrate them from time to time, for the value of 
their indicated deflections tends to alter as the strength 
of the controlling magnet dimmishes with the lapse of 

Vertical galvanometers in which the position of the 
needle depends partly upon gravity, and partly on the 
magnetic strength of the needle, are also liable to read 
too low as the needle gradually loses its magnetism. 

Horizontal galvanometers of the type figured above, 
figures 51, 52, are free from these objections; in these 
the position which the needle takes up is the resultant of 
two forces, viz., the attraction of the earth's magnetism 
tending to hold the needle in the magnetic meridian, 
and the attraction of the field of force of the coils tend- 
ing to draw it into a position at right angles to this. 
Changes in the magnetism of the needle do not alter 
the relation which the two opposing pulls bear to one 
another, and therefore the deflections of the needle are 
not altered if the magnetism of the needle becomes 

87. Ammeters and Voltmeters.— Galvanometers 
which are calibrated and marked to give readings 
direct in amperes or in volts are called by the above 
names. They assume many forms, and are specially 
wound to suit the currents or voltages they are to 
indicate. In medical practice it is not often required 
to measure currents of a magnitude of several amperes 
unless one wishes to know the strength of current 



needed for lamps or cauteries. In general an ammeter 
has a very low resistance, and must not be coupled 
direct to the terminals of an accumulator or to the main 
supply without some instrument or other resistance in 
the circuit to protect it from being overheated. 

Voltmeters on the other hand generally have a high 
resistance. The most convenient way of measuring the 
electromotive force of a medical battery is to use its 
own galvanometer, and by a simple calculation from 
Ohm's law the voltage of the cells can be calculated as 
follows : — 

Supposing the resistance of the galvanometer to be 
25 ohms, and a resistance coil of 975 ohms be con- 
nected to the terminals of the battery ; the total resist- 
ance in circuit will be 1000 ohms. 

Now one volt acting upon a resistance of one thou- 
sand ohms will cause a current of one-thousandth of an 
ampere to flow, that is to say one milliampere. With 
five volts, five milliamperes and so on. The readings 
of the galvanometer in milliamperes will therefore ex- 
press the electromotive force of the cells in volts if the 
resistance of the circuit amount to one thousand ohms ; 
the slight correction for internal resistance of the cells 
may be disregarded. This method has the advantage 
of measuring the electromotive force under conditions 
like those for which the battery is to be used. 

Instrument makers supply, if required, a resistance 
coil properly wound to bring up the total resistance of 
the galvanometer circuit to a thousand ohms, in order 
to simplify this mode of measuring the electromotive 
force of the cells of a medical battery. With this it 
is very easy to test the voltage of the individual cells 
by taking readings of the galvanometer while switching 
on the cells one after another. Each cell may be taken 


separately if the battery have a double collector, § 80 ; 
if it have a single collector, the increase of reading for 
each cell added may be taken to represent its electro- 
motive force. 

There are many other types of voltmeter for other 
purposes. Cardew's consists of a long and fine platinum 
iridium wire which is heated by the current, and ex- 
pands, moving a pointer which indicates the expansion 
on a specially calibrated dial. Ayrton and Perry's is a 
coil or solenoid, which draws a soft iron core into it, 
and the movement is indicated on the dial by a very 
ingenious spring invented by them. The electrostatic 
voltmeter is an adaptation of the principle of the mutual 
attraction of oppositely charged bodies. It uses no cur- 
rent, and will read equally well on either continuous 
or alternating circuits above fifty volts, as also does 
Cardew's. All these instruments are calibrated by the 
makers to read in volts, but should be checked from 
time to time by a competent person. 

88. Voltameters. — The periodical testing of a gal- 
vanometer is best carried out by comparing it with a 
standard instrument or else by means of a voltaineter. 
The latter method is an electrolytic one ; and consists 
in passing a current through the galvanometer and an 
electrolyte for a measured time ; and determining the 
amount of chemical decomposition which has been pro- 
duced, § 37, from this, the current can be calculated 
and compared with the readings given by the galvano- 

In the water voltameter the products of electrolysis 
are the gases Oxygen and Hydrogen, and these are 
collected and measured in some conveniently designed 
apparatus. Ten milliamperes of current will liberate 
I '056 cubic centimetres of mixed gases in ten minutes. 


The electro-deposition of metallic silver or copper from 
their solutions, may also be used for voltametric pur- 
poses by weighing the metal deposited after a measured 
period of time. See Ayrton, " Practical Electricity," 
Chap. I. and VIII. 

89. Practical note. — In concluding this short ac- 
count we would remind the reader that there are few 
things so difficult to follow in all their vagaries as the 
connections of electrical apparatus. Probably at first he 
will find considerable difficulty in making the simplest 
piece of apparatus work. But he need not, therefore, 
jump to the conclusion that the battery or galvanometer 
or instrument that he is using is out of order, and that 
the instrument maker need be sent for to put it right. 
The connections should first be examined and in all 
probability the fault will be found there. It is a very 
good thing to draw a diagrammatic plan of these and so 
check them off and make certain that all wires are con- 
nected up in the intended way. It is of course under- 
stood that the values of the various electromotive forces 
and resistances in the circuit have been so arranged as 
to give the required effect. If things will not go right 
then, the resistances and electromotive forces of the 
batteries should be taken, and it will be quite time 
enough to apply to the instrument maker when some- 
thing has been found to be wrong with these. A little 
intelligence in the application of theory will often save 
much cost and trouble in practice. 



Electricity of High Potential. Statical 

Historical. Description of instruments. The Holtz machine. 
Wimshurst's machine. Conductors and electrodes. Treatment 
by charging. The static breeze. Treatment by sparks. The 
Leyden jar. Static induction. Effects of static treatment. 
High frequency and high potentials. D'Arsonval's experiments. 
Their physiological and therapeutic effects. 

90. Introductory. — In comparing the so-called 
Electrostatic or Statical methods with other kinds of 
electrical treatment, it is found that an important 
feature of the former is, that very high electrical poten- 
tials even up to a hundred thousand volts or more are 

These enormous voltages can usually be applied to 
patients without danger, because of the small capacity 
(§ 18) of the machines commonly employed for pro- 
ducing them. The actual current in the discharge from 
an electrical machine is very small. Any rise in the 
capacity of the apparatus is accompanied by an increase 
in the magnitude of the discharge and in the sensation 
of shock, thus machines with large prime conductors, or 
those which have their capacity greatly augmented by 
Leyden jars (§ 20) may give shocks which are severe or 
even dangerous. 

91. Description of instruments. — The first form 
of electrical machine was a large sulphur ball which 
was excited by one hand as it was revolved by the 


other. It was made by Otto von Guericke of Mag- 
deburg in 1672. Some interesting reproductions of 
old figures of early electrical machines are given by 
Dr. Mount Bleyer, of New York, in Bigelow's " System 
of Electro-Therapeutics." Subsequently resin was used 
and then a glass cylinder instead of the sulphur ball. 
In 1740 Winckler excited the glass by means of horse- 
hair cushions covered with silk instead of the hands. 

In 1760, Ramsden substituted a circular glass plate 
for the cylinder, and his apparatus was until recently in 
common use. In Ramsden's machine electrical separa- 
tion is produced by the friction of the glass disc between 
two sets of cushions. 

In most modern machines induction is utilized for 
producing the electrical separation, and on this account 
they are often known as influence or induction machines. 
In 1865, Holtz of Berlin invented a machine which, 
when charged from an electrophorus would continue to 
produce electrical separation by induction. This form 
of machine proved to be far superior to the older fric- 
tional machines, and quickly supplanted them in spite 
of certain drawbacks. In its original form the cutting 
of its plates presented difficulties, it required to be 
excited from a separate machine or electrophorus before 
it would begin to work, it was liable to lose its excita- 
tion if worked upon open circuit, and it had a tendency 
to reverse its polarity during action. From its good 
qualities it has been made the object of much work in 
the hope of remedying its defects, and it has been 
brought to a high degree of perfection by the instrument 
makers of the United States where the Holtz machine 
is in almost universal use for electro-therapeutics. 

92. The Holtz machine. — In its simplest form it 
consists of two plates of glass. A, B, one having a 



diameter slightly greater than the other. The larger 
plate is fixed, but the smaller one is made to rotate by 
means of a cord and pulley, its axle passing through a 

hole in the centre of the larger plate. The plates are 
quite close together but do not touch. In the fixed 
plate are two windows, a, b, diametrically opposite to 
each other. Two pieces of paper called "field plates" 


are glued on to the fixed plate, one above the window 
on the left side and one below the window on the right. 
They are on the surface of the plate away from the 
revolving one. A tongue from each of these pieces of 
paper, protrudes through each aperture and nearly 
touches the revolving plate. The plate is rotated in an 
opposite direction to that in which the tongues point. 
Near the outside of the revolving plate are two brass 
combs, g, i, supported by two brass rods with knobs, /, 
forming the prime conductor. Two smaller brass rods, 
with ebonite handles, and two small brass balls act as 
electrodes and slide through the knobs at their other 
ends. These smaller balls can be approximated and 
withdrawn from each other by means of the handles 
and in that way the length of spark can be regulated. 
The rod t v is called the neutralising rod and is said 
to make the machine less likely to reverse. Before 
starting the machine one of the field plates must be 
charged from an electrophorus. The knobs of the dis- 
charging rods are to be brought together. The move- 
able plate is then rotated rapidly and sparks will pass 
between the electrodes when they are separated. 

In the modern machines used in electro-therapeutics 
there are many modifications in details. First the 
machine has four, six or eight pairs of plates and is 
enclosed in an air-tight case. The fixed plates instead 
of being round, with windows and a hole for the axle 
are oblong and are held in place by grooves in the 
framework of the case, and each is made in two pieces 
which do not quite touch each other and so leave room 
for the axle to revolve between them. The " field 
plates " of paper are glued to the fixed plates on the 
side which faces the rotating plate or near side, instead 
of being on the opposite or far side. This prevents the 


reversals of polarity during action which occurred with 
the original Holtz machine, by preventing the forma- 
tion of an accumulated charge of opposite sign on the 
near side of the fixed plate, as used to be the case when 
the field plate was attached on the far side. 

The machines for electro-therapeutics from the 
United States usually have revolving plates thirty 
inches in diameter ; the case is of glass with a stout 
framework of wood which carries the axle, and is 
pierced for the prime conductors. These are insulated 
by thick rods of ebonite where they come through the 
side of the case, and terminate in large knobs fitted 
with sliding discharging rods. The machine is driven 
by a belt and pulley, either by hand or by an electric 
or other motor. For providing the initial charge which 
is required to excite the action of the machine a small 
Wimshurst machine is fitted in the corner of the case 
with gearing by means of which it can be started and 
stopped as required. 

93. The Wimshurst machine. — The Wimshurst 
machine has the advantage over the Holtz that it is 
self exciting, and its polarity will not reverse under 
ordinary circumstances while it is in action. It consists 
of two circular glass discs (or any even number up to 
twelve), mounted in pairs upon a fixed horizontal 
spindle in such a way that they rotate in opposite 
directions at a distance apart of not more than one- 
eighth of an inch. Each disc is attached to the end of 
a hollow boss of wood, or of metal, upon which is 
turned a small pulley. The pulleys are driven by a 
cord or belt from larger pulleys attached to a spindle 
below the machine, and rotated by a winch handle or 
by a motor, the difference in the direction of rotation of 
the discs being obtained by crossing the alternate belts. 



Both discs are well varnished, and attached to the 
outer surface of each there are radial sector-shaped 
plates of tin-foil or thin brass disposed around the discs 
at equal angular distances. These sectors are not 
essential to the action of the machine, but they make 
it more easily self exciting. With large machines and 
carefully adjusted neutralising rods (see next paragraph) 

Fig. 55. — Wimshurst machine. 

the presence of sectors is of no advantage, for such 
large machines excite quite readily without sectors. 

Twice in each revolution the two sectors situated on 
the same diameter of each disc are momentarily placed 
in metallic connection with one another by a pair of 
fine wire brushes attached to the ends of a curved rod, 
called the neutralising rod, supported at the middle of 
its length by one of the projecting ends of the fixed 


spindle upon which the discs rotate, the sector-shaped 
plates just grazing the tips of the brushes as they pass 

The position of the two pairs of brushes with respect 
to the fixed collecting combs and to one another is vari- 
able, as each pair is capable of being rotated on the 
spindle through a certain angle ; and there is one 
position of maximum efficiency. This position in the 
machine appears to be when the brushes touch the 
discs on diameters situated about 75° from the collecting 
combs, and 30° from one another. 

The fixed conductors consist of two forks furnished 
with collecting combs directed towards one another, and 
towards the two discs which rotate between them, the 
position of the two forks, which are supported on 
ebonite pillars, being along the horizontal diameter of 
the disc. To these fixed conductors are attached the 
terminal electrodes, whose distance apart can be varied. 
Leyden jars are usually fitted to the machine by the 
makers, but these must admit of their outer coatings 
being disconnected, before the machine is used for 
treating patients, see § 106. 

The machine is very efficient and perfectly self 
exciting, provided there are sufficient sectors, generally 
requiring neither friction nor any outside electrification 
to start it, and this is one of the most remarkable 
features of the apparatus, for under ordinary conditions 
the machine works at its full power after the second or 
third revolution of the handle. It has been suggested 
that this initial charge is obtained from the friction of 
the air, and that chiefly between the plates, but nothing 
certain is known about it. 

When the glass plates are very large they are apt to 
split. On this account a modification of the Wimshurst 



machine has been made with ebonite plates, which are 
said to be superior to glass, and are not Hable to break- 

FiG. 55.-Large Wimshurst machine or medical use, with platform, and electrode 
for head breeze. 

age during transit or use and can be safely driven at a 
very high speed. There is, however, a grave objection 
to the use of ebonite, as it gradually deteriorates on the 


surface and loses its insulating properties ; moreover, 
the plates of ebonite cannot be kept true, but bend and 
buckle, glass is therefore the best. 

Mr. Pidgeon has introduced modifications into the 
Wimshurst influence machine by adding fixed inductors 
to reinforce the action taking place between the plates, 
by increasing the size of the tin-foil sectors, and by 
very carefully insulating the sectors from leakage to 
each other, and in this way he has succeeded in increas- 
ing, very notably, the output of a machine of a given 
size as compared with the output of an unmodified 
machine having plates of the same dimensions. 

A Wimshurst machine for therapeutic work should 
have eight plates of thirty or thirty-six inches diameter. 
The figure shows one constructed for my own use by 
my friend Mr. C. L. Schwind. This machine, without 
any Leyden jars, gives streams of sparks of from nine 
to ten inches long, and serves admirably for all thera- 
peutic purposes. It is enclosed in a roomy case to 
prevent waste by leakage from the machine to the case, 
and to protect it from damp and from dust. It runs 
silently and smoothly and has not failed on any occa- 
sion. It is driven by a :^-horse electric motor. 

94. Medical applications. — Whether the Wims- 
hurst or the Holtz machine be adopted the essentials 
are the same, namely the machine must be large 
enough, it must be built to stand hard work and it 
must be enclosed in an air-tight case. The effects 
which large statical machines can produce are almost 
startling to those who have been familiar only with the 
phenomena produced by small machines, and the thera- 
peutic results of their use are obtained so easily and so 
promptly that it is a pleasure to use them. The pro- 
gress with Statical treatment in the last few years is 



due entirely to the work done by medical men in the 
United States. With characteristic enterprise they 

Fig. 57. — The American Holtz machine, medical type. (Waite & Bartlett 
Manf. Co., New York). 

have elaborated the Holtz machine and taken up the 
use of it so effectually that there are now in New York 
alone three firms making and selling Holtz machines in 



large numbers while one of these firms has just recently 
become established in London. 

In the summer of 1898 I had the pleasure of making 
the acquaintance of Dr. Monell of Brooklyn, the author 
of a large and admirable work called, " A Manual o^ 
Statical Electricity in X Ray and Therapeutic Uses." 
He very kindly procured for me from New York a set of 

Fig. 58. — Front of case, showing ebonite rod with connections to earth above and 
to platform below, and arrangement of poles. 

electrodes and apparatus for use with the static machine 
and delayed his departure from London until they 
arrived in order to give me a full practical demonstra- 
tion upon the modes of application which he had 
elaborated and was teaching in the Brooklyn Post 
Graduate School of Electro-Therapeutics. So attrac- 
tive was the field of work which his lessons revealed 
that I at once arranged to have a new Wimshurst 




machine built, with eight thirty-six inch plates to take 
the place of the one with four plates which I then had, 
and for what follows in this chapter I desire to make 
grateful acknowledgment to the instructions of Dr. 
Monell, both, as communicated personally and from the 
pages of his book, which is indispensable to any worker 
with the static machine. 

In the methods of treatment advocated by Dr. Monell, 
the patient is usually insulated upon a platform with 

glass legs, and is connected to one pole of the machine 
by a conductor ; the electrodes, whether knob, or point, 
or roller, are connected to earth, and the second pole 
of the machine is also earthed. The advantage of 
this mode of procedure, which is rendered possible by 
the power of modern machines, is that the instruments 
handled by the operator are at zero potential, and he 
therefore is not called upon to use any insulating 
device to protect himself from shocks. The earthing 
of the electrodes is arranged by a long light chain 


connected at one end to a gas or water pipe in the 
building, and fitted at the other end with a handle 
shaped like a Hail to which the electrodes are hung. 
This handle, or "electrode holder," of Dr. Monell is an 
ingenious contrivance, and serves to support the weight 
of the electrodes during their application. It is held in 
the left hand close to the body, and supports the weight 
of the electrodes somewhat as a crane supports a weight. 
Thus the right hand is used to hold and direct the 
electrode, while the left hand supports the weight of it 
and so relieves the right arm. 

A solid ebonite rod with brass terminal knobs is held 
in a wooden clamp between the dischargers of the 
machine (fig. 58). The upper knob is for the earth 
connection, the lower is for the connection to the plat- 
form. In this way either pole of the machine can be put 
to earth while the other is connected to the platform. 

95. Accessory apparatus. — The accessories which 
are essential for the proper use of a static machine are 
as follows : — A platform with glass legs, chains for earth- 
ing conductors, a single point electrode, a multiple 
point electrode, a brass ball electrode, a brass roller, and 
a Monell's handle for holding these ; also, a swinging 
brass rod carrying a wire tassel which is best attached 
to the case of the machine as shown in fig. 56. A brass 
adjustable stand to hold a fixed electrode, a sheet of 
brass for a footplate, and a connecting rod or wire to 
connect the patient, or the platform, to the machine. 
There are other electrodes for more special uses, and it 
may be of advantage to have Leyden jars arranged for 
use in certain cases. Their applications will be con- 
sidered in a later paragraph. 

Hitherto the demand in Great Britain for static 
machines adapted to medical purposes has been nil. 



It has therefore been necessary for me to have all the 
parts and fittings for the work made to order after my 
own instructions, and it may therefore be useful to 
others if I give the addresses of those who have made 
them for me in case others may want similar things. 
Thus the Wimshurst machine figured above is made 
by Mr. Lionel Schwind, of Broomfield near Derby, and 
cost £/\.2 ; the case for the machine and the platform are 
by Messrs. Allard and Co., of New Street, Bishopgate, 
costing from ;^i8 to ^30 according to the style and 
finish of the workmanship. The prime conductors and 
dischargers by Mr. L. Miller, of 93 Hatton Garden. 
The electrodes I had from Messrs. Van Houten and 
Ten Broeck, of 300 Fourth Avenue, New York, who 
also can supply glass legs cast with a screw thread at 
their upper ends for convenience in fitting ; they supply 
the outfit of electrodes for ;^io. The establishment by 
Messrs. Waite and Bartlett, of New York, of a branch 
house in London at 18 Pall Mall East, will enable 
medical men in this country to provide themselves with 
a complete outfit with a Holtz machine without trouble 
and delay, and Messrs. Watson and Sons, of High 
Holborn, are prepared to supply an outfit resembling 
my own with a Wimshurst machine and all accessories 
complete. It is likely that the advantages of statical 
treatment may gradually become recognised in this 
country, particularly, now that the same machine will 
also serve for X ray work. 

96. The insulated platform. — This is a most im- 
portant part of the outfit. A bad platform may reduce 
the efficiency of the treatment by one half through 
losses of charge from leakage. To reduce these losses 
as far as possible the platform must be made with all 
corners and edges carefully rounded off and made 



smooth, the glass legs should be at least ten inches long 
and twelve inches is even better. There should be a 
rounded beading or edging to the platform to prevent 
the chair or stool from slipping off through any move- 
ments of the patient. The dimensions recommended by 
Monell are forty-two inches by twenty-seven. The 


Fig. 60.— Electrodes. 

platform and the glass legs must be strong enough to 
support the weight of the heaviest patient. Owing to 
the size of the platform it is useful that the case of the 
machine shall be so built as to permit of the platform 
being pushed underneath it when not in use, otherwise 
the platform takes up a great deal of floor space. 

97. Electrodes. — Fig. 60 shows the four chief elec- 

1 66 


Fig. 6i.— Stand electrode. 


trodes, namely the single point, the multiple point, the 
knob or ball electrode and the roller. The eye at the 
side of the electrodes is for attachment to the Monell 
handle, while the eye at the ends is for hanging up the 
electrodes upon hooks when they are not in use. Fig. 
61 shows a stand with combined ball and point elec- 
trode ; it is useful in certain applications, the stand is 
hinged at the top and can be raised and lowered to 
bring either the knob or the point into any desired 

The single point electrode is used for giving the static 
breeze, and the multiple point is for the same purpose, 
its effect being rather stronger. The ball electrode is 
three inches in diameter and is used for administering 
sparks. The roller also gives spark discharges but in a 
special way. It is used by rolling it over the surface 
(clothed) of the patient. When this is done showers of 
very short sparks are given off, of a length equal to the 
thickness of the layer of clothing between the roller and 
the skin. These short sparks produce a very strong 
sensory effect, and the roller electrode must therefore be 
used only with very rapid movements, otherwise the 
sensation becomes unbearable. It is a most valuable 
instrument in certain conditions and its effects are 
highly stimulating. 

98. Distinction of poles. — To test the polarity of 
the machine. Take the earthed point electrode in the 
hand and present it to a knob of the machine in action. 
Gradually bringing it nearer and nearer, as it approaches 
the positive knob a star of light will appear on the point 
even at a distance of several inches, and this star of 
light will remain without much alteration until the 
point is brought up almost into contact with the knob, 
then small sparks pass. If approached to the negative 


pole in the same way the discharge takes the form of a 
visible brush or spark when the point is still at a dis- 
tance of two or three inches from the knob. It is easy 
to recognise these differences in the discharge to the 
point, and from them to know which pole is positive 
and which the negative. 

99. Operative procedures. — The patient is to be 
seated on a stool or chair on the insulated platform, and 
the brass plate connected with the machine by a wire 
or chain or brass crook. On the brass plate is placed a 
thick bundle of newspapers (of about the size of the 
" Illustrated London News ") and on that the patient 
rests his feet. The machine is then set in action and 
its polarity tested. Then bring the positive or the 
negative pole into contact with the conductor to the 
platform and take the other one to the earth connec- 
tion (fig. 58). The patient is then charged positively 
or negatively as the case may be. The presence of 
nails in the seat of the stool is undesirable. 

100. Simple charging or electrification. — As soon 
as the patient becomes charged he feels certain sensa- 
tions. The hair begins to move, and on the scalp and 
face and to a less degree on other parts he feels as if 
lightly touched by gossamer or cobwebs. If any piece 
of furniture or other object or person be near he may 
feel a breeze blowing towards him from it. If the 
platform is too near the machine this breeze will be 
particularly felt from the direction of the grounded pole 
of the machine. The platform therefore should be two 
feet or more away from the side of the machine and 
from any furniture or the walls of the room, and the 
friends of the patient must be warned not to touch or 
hand anything to the patient, otherwise a spark will 
pass between them and both will receive a shock. 


Simple charging (positive or negative) may be con- 
tinued for fifteen minutes or longer. Its effects are 
agreeable and tonic. It is the mildest form of statical 
treatment and is usually given not alone, but combined 
with the breeze to the head or spine or both, it is also 
a necessary part of all statical treatment administered 
to a patient on the insulated platform. Usually the 
patient is charged positively because that is the natural 
condition of charge of a patient in the open air or on a 
mountain side. It has been said that the negative 
charge produces feelings of prostration while the posi- 
tive produces invigoration. This is probably incorrect 
at least it is not supported by everyday experience, 
though the idea serves to decide that when simple 
charging is desired the positive charge shall be pre- 

loi. Charge and discharge. — In addition to the 
continuous electrification described in the last para- 
graph, there is a method of alternately charging and 
discharging the , patient which is described by Dr. 
Monell, and recommended by him as a more energetic 
tonic treatment than the simple charging. He has 
given it the name of " Potential Alternation," and it is 
performed as follows : — While the patient is being 
charged, the knob or ball electrode, grounded as usual, 
is brought near to the knob of the machine from which 
the patient is being charged. As it approaches, a sharp 
cracking spark passes and the patient is discharged, to 
be immediately charged again from the machine and 
again discharged in the same way as before. The 
chargings and dischargings follow each other with a 
rapidity which depends upon the activity of the machine 
and the width of the gap across which the spark must 
leap. The patient's hair can be seen to oscillate in 


t^ime with the sparks, especially if the head breeze 
electrode be in position during the application. This 
method has the disadvantage that the stream of sparks 
makes a distracting noise which some patients cannot 
endure. Other patients do not mind the noise so much 
and find the application not unpleasant. 

102. The breeze or brush discharge. — If when 
the patient is charged on the platform, a grounded 
point electrode is presented to him he feels the sensa- 
tion of a wind blowing towards him from the point ; 
this is the electric breeze, or wind, or souffle electrique. 
It can be felt when the point is a yard away, but 
becomes much more strongly felt when the point is 
brought nearer, right up to the distance at which the 
discharge changes from the silent discharge to that of 
sparks. The safe distance varies according to the 
polarity of the patient. When he is positive the 
grounded point can be brought much closer without 
sparking than when he is negative. The breeze which 
is felt as a cool wind upon the bare skin acquires a 
pricking hot character when directed upon covered 
parts and the prickly sensation is greater when the 
patient is positively charged. Usually, therefore, the 
patient is charged positively, except when the mildest 
form of breeze is desired, as may be the case with timid 
or unaccustomed patients. The breeze produces a very 
grateful sensation when applied to the scalp, and to the 
nape of the neck, and it is usual to arrange a special 
electrode for this head breeze by means of a hinged arm 
supporting a wire tuft or tassel, or a crown shaped 
metallic arrangement. In figure 56 this is shown as a 
rod projecting out from one top corner of the case, it 
has an universal joint enabling it to be swung out or in 
and raised or lowered to bring it into place over the 


patient's head as he sits upon the platform. The scalp 
can also be '' breezed " by the point electrode held in 
the operator's hand. 

The breeze is called the " negative breeze " when the 
patient is positive and vice versa. The breeze can be 
varied in strength by varying the distance between the 
point and the patient's surface. When the strongest 
effects are desired, the point (single or multiple) is 
brought as close as is possible without sparking, the 
effect then is something like a douche of hot water, and 
may be so strong as to be unpleasant, especially if kept 
acting for long upon one spot. It is more easily borne 
if the electrode is kept moving over the surface. The 
effect of a strong negative breeze upon the spinal region 
and the back is very invigorating, and it leaves a warm 
glow or after effect. As the effect of clothing in modi- 
fying the sensations of the breeze discharge is so 
marked it is occasionally useful to vary the thickness 
of the clothing to suit the requirements of the case, and 
this can best be done by using a woollen shawl, which 
may be thrown over the patient at any part where the 
strongest stimulation is desired. All the fabrics used 
for clothing do not behave alike in modifying the sensa- 
tions produced by the breeze, for occasionally the 
corsets (or the back of the waistcoat in the case of male 
patients) may prevent the breeze from penetrating 
satisfactorily. It is not often, however, that difficulties 
arise, and when they do it is generally possible to 
overcome them. Occasionally the metal parts of the 
stays, or buckles, or hair-pins, or fine gold chains 
worn round the neck, or a steel key chain in the side 
pocket will cause some pricking or discomfort at the 
wrong place, and must be attended to. 

When the patient's skin and underclothing is very 


moist from perspiration the effect of the breeze is 
greatly diminished, and occasionally in very close 
summer weather the roller must be brought into play 

The breeze may be modified and strengthened by 
interrupting the charge as it passes from the machine 
to the patient ; this is easily done by moving the con- 
ductor of the machine a little distance from the knob 
which leads the current to the platform. 

The effect of the breeze is to produce profound 
cutaneous sensory impressions which can be adjusted 
so as to be either soothing or highly stimulating. In 
many cases of neuralgic pain, including headache, the 
effect is quite magical, that is to say, the breeze skil- 
fully directed upon the affected region for five or ten 
minutes will often remove the pain entirely. In addi- 
tion to this local effect, which is often very valuable, 
there is a general invigorating effect from the breeze 
applied to the head, the nape, and the spine, for which 
patients are very grateful. The sensations may be com- 
pared to the effect of those douches used in hydropathic 
establishments, with the great advantage that they can 
be given to the patient without any removal of clothing. 

103. Treatment by sparks. — For giving sparks 
the knob electrode is used and as the sensation of a 
spark is disagreeable they must be given in as skilful a 
way as possible to avoid all unnecessary discomfort to 
the patient. The important point is to give only one 
spark at a time and not a volley. To do this the knob, 
earthed as usual, is swept quickly in a curve past the 
place at which the spark is aimed so that it is away 
again and out of range before a second one can follow 
the first. With a little practice this becomes easy. 
The sparks may be repeated as often as it is judged to 


be necessary. Long sparks must not be directed upon 
bony prominences nor upon any place where the bone 
is thinly covered with soft tissues, and great care must 
be taken to prevent any spark, accidental or other, to 
the testicles or to the female breast, or to the face. 
The length of the spark can be decreased by partially 
discharging the patient before giving the spark, and 
this is easily done by the operator placing his foot upon 
the edge of the platform, and so causing it to leak away 
part of its charge. Sparks from a knob are more severe 
than those from the point or roller ; the sensation pro- 
duced by a single well directed spark is just that of a 
blow, the sensation of a blow or shock depending mainly 
upon the sudden forcible muscular contraction caused 
by the spark. It is as well to give the patient notice 
just before each spark. With ladies the sparks must 
usually^ be weakened in the manner indicated. 

104. The roller : electric frictions. — When the 
roller is rolled over a clothed surface showers of short 
stinging sparks pass off from it to the patient, and the 
thicker the layer of clothing under the roller the sharper 
are the sensations. Thus they can be made stronger 
by a woollen shawl thrown over the clothing, and 
milder by the removal of an outer garment. The sen- 
sation is severe and leaves a tingling glow behind it 
which persists for some time. To use the roller it is 
best first to discharge the patient by means of the foot 
on the platform, and then quickly to put the roller in 
place, withdrawing the foot and sweeping the electrode 
over the surface immediately. All should be done in a 
few seconds, or the patient may protest. As in the case 
of long sparks, patients like to receive notice of the 
roller if it is to be applied to any part of the back where 
they cannot see it coming. 


105. The Leyden jar. — This apparatus (see § 20) 
was discovered in 1749. Owing to the arrangement 
of its coatings it has a large capacity, and in its dis- 
charge there is a larger "current" than in the spark 
from the prime conductor of a machine as ordinarily 

This makes itself felt as a more severe shock, when 
the discharge takes place through any portion of the 
body. The Leyden jar is therefore used when it is 
desired that the patient shall receive a painful shock. 

In former days the comparative feebleness of the 
machines in use made it necessary at times to use 
Leyden jars to secure the strong effects which can now 
be produced more agreeably by the ordinary spark dis- 
charge from a knob electrode. They were used by first 
charging them from a machine and then bringing them 
to the patient and discharging them through him by 
means of conductors. They were also used in connec- 
tion with an apparatus known as Lane's discharger, 
with ordinary cords and electrodes, like those described 
in the last chapter, and in a book on " Electricity and 
Medical Electricity" written by Adams in 1791, the 
frontispiece illustrates a physician of the period electri- 
fying the muscles of a child's forearm in this manner. 

This mode of treatment, however, seems to have been 
completely forgotten, for it is not mentioned in later 
writings so far as I am aware. In recent years an 
analogous method of using Leyden jars has been de- 
vised and brought to perfection by Dr. W. J. Morton of 
New York, and, as worked out by him, it has now 
become a very useful part of a statical outfit and has 
met with universal acceptation. 

106. Dr. Morton's method. — In the illustration of 
the Wimshurst machine (fig. ^^), two Leyden jars are 


shown with their inner coatings connected to the prime 
conductors, one to each ; the outer coatings are also 
connected by a wire, which can be removed at will. 
When the outer coatings are disconnected, or the jars 
are removed entirely, the machine in action produces 
a stream of thm purplish sparks, and if the finger be 
placed between the discharging electrodes, the sensa- 
tions, though unpleasant, are of the nature of a slight 
pricking rather than of a shock. If the jars are now 
connected to their respective electrodes, and their outer 
coatings are joined by the wire, the sparks between 
the electrodes alter their character, becoming less 
numerous, much brighter, much longer and much more 
noisy. They also produce severe shocks if the fingers 
are placed in their path. As the distance between the 
knobs of the discharging electrodes is increased the 
sparks become louder, more vivid and less frequent, 
until the air gap is too great for the discharge to cross. 
The Leyden jars are fitted to the machines to make 
their discharges more powerful. If the wire joining the 
outer coatings of the jars be interrupted by a short air 
gap, sparks will leap across it simultaneously with those 
passing between the electrodes. 

Many machines are fitted with a pair of binding 
screws in the circuit joining the outer coatings of the 
Leyden jars. This makes it easy to connect or dis- 
connect this part of the circuit. When a wire is used 
to bridge over the interval between the binding screws 
the outer coatings are connected, when it is removed 
they are disconnected. Dr. Morton of New York has 
advocated the use of this portion of the circuit between 
the outer coatings for purposes of treatment. With 
a pair of ordinary conducting cords and electrodes 
(fig. 62) attached to the binding screws mentioned 



above, Leyden jar shocks can be administered to a 
patient, and their severity can be controlled by adjust- 
ing the distance between the discharging knobs of the 
prime conductors. When the machine is in action a 
shock is felt by the patient every time a spark passes 
between the discharging knobs. Dr. Morton has given 
this method the name of treatment by "static induction," 
and the utiHty of the method is undoubted for purposes 
of treatment. Further, Dr. Morton has claimed that 

Fig. 62 — Plan of Dr. Morton's method, a. Plate of machine, b. Collect- 
ing combs, c. Prime conductors, with discharging rods, d. e. Leyden jar. 
g. Wires and electrodes attached to their outer coatings. 

by the use of very small Leyden jars and with the dis- 
charging knobs very close together, the shocks become 
almost painless, while still setting up vigorous contrac- 
tions in the muscles, and may then be made extremely 
useful for purposes of testing. It is doubtful, however, 
whether this method is less painful than the discharge 
of a well designed induction coil. 

It is of the utmost importance to adjust the sparking distance 
between the discharging electrodes on the machine before com- 


mencing the treatment ; from an eighth to a quart ev of an inch 
is generally sufficient ; indeed, with quarter inch sparks, the 
treatment is severe ; hut the severity of the shock depends also 
upon the size of the jars, and is more severe with large jars. 

Modern statical machines for medical treatment are 
now generally fitted with pairs of Leyden jars of several 
sizes for Morton's method, and have a simple switch 
arrangement for connecting or disconnecting the jars as 
required. The rate at which the shocks follow each 
other is determined by the speed of the machine. The 
effect produced is comparable to that of a slowly acting 
induction coil, and moistened electrodes applied to the 
bare skin are to be used. 

By a further application of a helix of wire between 
the outer coatings effects like those of the Tesla coil can 
be obtained, see below, § no. 

107. General effects of statical treatment. — We 
may distinguish two sets of effects produced by statical 
applications ; the one a general one, the other local. 
The former, though vague in description, is yet of quite 
definite nature and can perhaps best be called a general 
stimulating or "invigorating" tonic effect. The patient 
becomes more bright and alert, feels more lively and 
generally is improved in health if ailing or fatigued. 
For example, a medical man, who came to see my 
machine in order to be instructed in its use, was 
charged on the insulating platform and received an 
application of the negative breeze to the head and 
spine. After a few minutes he said that he had slept 
badly the night before and had been feeling very 
uncomfortable and tired but that the application had 
completely removed his discomfort. Statements of that 
kind from patients are not at all unusual. In morbid 
conditions of debility from various causes this effect of 



the static machine can be of considerable permanent 

108. Clinical experiences. — Dr. Imbert de la 
Touche has obtained results which tend to support 
the view that the electrostatic charge modifies the 
metabolic processes in some way. He has reported 
cases of obesity cured by this method, and speaks with 
confidence of its great value in "obesity of nervous 
origin," particularly when anaemia, headaches, and 
insomnia co-exist. 

Dr. Dignat examined the pulse-tension in eleven 
patients and found that out of sixty- two observations 
the tension was raised in thirty-six, remained unaffected 
in twenty-four, and was lowered in two. 

Dr. Vigouroux has expressed the opinion that the 
treatment by electrostatic charge acts chiefly upon the 
function of nutrition and upon the nervous system. 
Sleeplessness and languor disappear soon after the 
commencement of the treatment, the appetite too be- 
comes increased ; as for the urine, the urea augments 
and the uric acid diminishes, and the flatulent dyspep- 
sia, so common in neurasthenics, is rapidly ameliorated. 

Statical applications undoubtedly act upon the func- 
tion of menstruation. With patients receiving a course 
of treatment for conditions quite unconnected with the 
generative functions it is common to remark some effect 
upon the menstrual periods. Professor Doumer'-' of 
Lille has published his notes on 400 women treated by 
static electricity. In 342 the uterine functions were 
quite normal ; in the rest, 58 in number, there was 
some complaint of menstrual trouble, mainly of the 
nature of dysmenorrhoea. Among these patients there 
was a hastening of the commencement of the period in 
* Archives d^clectricite tnedicale, 1897, p. 96. 


68 per cent., and an increase of the flow in 77 per cent. 
Among the 400 cases there were 178 who had some 
pains or discomfort about the date of the commence- 
ment of their periods, and 73 per cent, of these, 130 
persons, were reheved of these symptoms, while the 
remainder were not. Menstrual irregularity was 
present in 51 cases and quickly disappeared in 31. 
These results followed for the most part upon simple 
electrostatic charging but the breeze or the roller 
applied to the lumbar region produced a more prompt 

Truchot''' has reported the results of some experiments 
upon himself, in which he was charged once or twice 
daily for a week. Each charging period was of fifteen 
minutes duration, but it is not specified whether the 
charging was positive or negative. The points attended 
to were the pulse-rate, the temperature, and the urine ; 
the force of the grasp was also determined by means of 
a dynamometer. These points were observed for the 
week preceding the commencement of the electrifica- 
tions, and for the week which followed. 

The pulse was increased in frequency after each 
charging, being raised from 65 to 80, but apart from 
this immediate effect there was also a gradual rise in 
the average daily rate so that after the fifth or sixth 
charging the pulse remained at 80 for the whole day, 
and only began to return to its normal frequency two 
days after the chargings had been discontinued, finally 
reaching its normal rate of 65 per minute at the end of 
a week. The temperature also showed a gradual rise, 
being 97-9 at the beginning of the treatment, and 99-3 
at the end of the week, returning slowly to its former 
level during the next few days. 

* Archives d^electricite tnedicale, Feb., 1894. 

N 2 


The strength of grasp was augmented by each 
charging, rising from 42 to 44 kilogrammes after the 
first time ; from 41 to 43 after the fourth, and from 40 
to 42 after the sixth, but, as these figures show, there 
was a progressive decrease in the muscular power 
during the week of treatment, and the decrease was 
gradually recovered from during the following week, 
when charging had been discontinued. 

The analyses of the urine, though a little difficult to 
interpret, show at first an increased proportion of urea 
to total nitrogen, followed by an increase in the total 
nitrogen with a fall of urea, which Truchot interpreted 
by supposing that at first metabolism was increased 
and internal oxidation was improved, but that after- 
wards there was increased tissue waste with less perfect 
oxidation ; here again the effects of the treatment were 
perceptible for several days after its discontinuance. 
His general condition showed increased appetite for the 
first day or two followed by a diminution ; sleep became 
disturbed, and a feeling of languor and feverishness 
developed itself. Thinking that perhaps the season of 
the year (July and August), and the fatigue of the 
summer session might have contributed to his weariness, 
the experiments were repeated between Oct. 15th and 
Nov. 15th after the repose of the long vacation. The 
results, however, were precisely the same, the tempera- 
ture rose from 98-6° to 99° after four sittings. The 
pulse rose from 64 to 79, the feelings of fatigue returned. 

The body weight does not seem to have been taken, 
and no light is thrown upon the question of the differ- 
ence between the effects of positive and negative poles. 

Of more importance than the experiments last noted 
are the numerous clinical results which are observed in 
the treatment of various forms of general or of nervous 


debility. Dr. Monell reports strongly on its value in 
cases of neurasthenia in its various forms, and in the 
treatment of insomnia and mental fatigue ; and he 
quotes from several recent writers on the subject of 
the treatment of certain forms of insanity and morbid 
mental states in which favourable results have followed 
statical applications, particularly in melancholia. In 
the nervous disturbances about the time of the meno- 
pause I have seen very decided benefit from simple 
static charging with the use of the negative breeze. 

109. Local applications. — In the second class of 
local effects, the action depends very greatly upon the 
peculiar stimulation of the sensory nerves of the skin 
which can be produced by local applications with the 
point or roller electrode. 

These sensory impressions can be made to vary from 
a cool and gentle breeze effect to an intensely pungent 
pricking, and much of the success of static applications 
depends upon the adjustment of the degree of cutaneous 
stimulation to the nature of the individual case. It is 
in this wide range of the sensory stimulation and in its 
peculiar qualities that much of the value of the machine 
for the rehef of painful states lies. 

The effect of breeze discharges upon painful affections 
of cutaneous nerves, as, for example, in headache, in 
neuralgia, or in neuritis with pain, is very striking. 
One may often see patients move so as to bring the 
tender area more directly into the line of the discharge, 
as though to obtain the fullest effect, and often they 
may be heard to utter expressions indicative of the 
immediate relief they are deriving from the application. 
With the negative point (the patient charged positively) 
there is not much risk of unintentional sparks, for 
sparking does not occur except with the point at very 



close quarters. When for any special reason the 
patient is negatively charged, and the point therefore 
is positive, sparks may occur even across a distance of 
four inches or more, and must be guarded against. 

The most intense cutaneous stimulation is that pro- 
duced by the roller electrode ; and the severity of the 
application demands that it shall be used only for brief 
periods of a few seconds at a time. Regard must also 
be had to the thickness of the layer of clothing over 
which the roller is moved, as the sparks will be longer 
and stronger with a thicker layer. In approaching the 
roller to the patient a quick movement is necessary, to 
reduce the number of the stray sparks which pass as 
soon as the roller comes within striking distance. They 
can also be diminished by partially discharging the 
the patient by placing one foot on the platform until the 
roller has come into contact with the patient. 

The action of the breeze upon the skin itself is shown 
by its effects in certain skin diseases. It has been fre- 
quently noticed by others and it has also come under 
my own observation that patients receiving applications 
of the breeze to the scalp find that the hair ceases to 
fall out. In pruritus, which is so intractable to many 
forms of treatment, the breeze has a markedly beneficial 
effect. In psoriasis, eczema, and varicose ulcers of the 
leg the same is true. 

The local action of a strong breeze upon the skin 
through woollen clothing remaining plainly visible for 
some hours afterwards in a persistent reddening or in 
the form of urticaria-like elevations. 

In addition to effects produced by means of cutaneous 
sensory stimulation, we have the shock or commotion of 
the contractile tissues which is produced by the appli- 
cation of a spark from the knob. This shock relieves 


many deep seated pains of a myalgic nature, and often 
relieves them instantaneously. Probably it acts, in 
part at least, by a sort of forcible wrenching of muscle 
fibres. Often it is useful to request a patient with a 
pain in a muscle to assume an attitude which provokes 
the pain or increases it, and then to apply the spark or 
sparks to the painful part. In lumbago, deltoid rheu- 
matism and other so-called rheumatic muscular pains, 
the treatment by sparks relieves promply. 

no. High frequencies and high potentials.— 
The introduction of alternating currents for commercial 
purposes, and the ease with which high potentials can 
be obtained through their use by the aid of trans- 
formers makes it possible to subject the body to alter- 
nating high potentials and to examine the physiological 
effects produced. With the electrostatic machine the 
process of insulation and charging raises the patient's 
body to a high potential, positive or negative, according 
to choice, and the potential is maintained during the 
action of the machine. By attaching an insulated 
patient to one pole of a high pressure transformer a 
charge which is alternately positive and negative can be 
applied to him. The experiment is not to be under- 
taken without the most careful insulation. If the 
patient should by any accident become connected to 
earth during the charging, as might happen in various 
ways, as for example, by being touched by a bystander, 
his body would become the channel for a current to 
earth which might easily attain a dangerous magnitude ; 
and as a matter of fact many persons have been killed 
by coming into contact with a high potential conductor 
when they were not properly insulated from earth. It 
has been already explained why there is no danger of 
accident with the electrostatic machine (§ 90) and it is 


quite possible to arrange matters with the transformer 
so as to get rid of all serious risk by the use of adequate 
resistances, or of transformers of very high self-induc- 
tion and small output. No experiments, however, have 
yet been made in this direction ; and the effects of a 
high potential charge alternating at the rates usual in 
commercial currents, ranging between 50 and 120 com- 
plete periods a second have yet to be studied. 

High frequency experiments. — When a charged con- 
ductor discharges itself, it happens under certain con- 
ditions of the discharging circuit that the discharge is 
an oscillatory one, that is to say the direction of the 
discharge current is alternating. These oscillations 
quickly die away, but while present they may have a 
periodicity of millions per second. 

Of late years Elihu Thomson, Nikola Tesla and 
D'Arsonval have developed the study of these " high 
frequency " phenomena, and have obtained some re- 
markable results. The apparatus required is compara- 
tively simple ; the principle is to charge Leyden jars 
whose outer coatings are connected by a helix of wire, 
as in figure 63. The inner coatings of the jars terminate 
in knobs whose distance apart can be adjusted to suit 
the sparking distance of the charging electromotive 
force. The jars can be charged from a Wimshurst 
machine, or from an induction coil of large size, or, 
through a high potential transformer, frcm the alternate 
current supply mains. The output is greatest in the 
latter case and least in the first method. 

The jars when charged to a certain potential dis- 
charge across the air gap, and oscillations are set up in 
the helix connecting the outer coatings, and the helix 
becomes the seat of electro-magnetic induction effects, 
comparable to those of the primary circuit of an indue- 



tion coil, so that wires leading from the two ends of the 
helix yield a current, as do the wires of the primary- 
current of a coil. In fact the apparatus is a modified 
induction coil, the current being supplied from the jars 
instead of from a galvanic cell, while the spark gap 
takes the place of the contact breaker, and the sudden- 
ness of the discharge by causing very rapid changes in 

Fig. 63. — Arrangement of apparatus for high frequency experiments. 

the magnetic field of the helix, sets up very powerful 
induction effects, both in the helix itself (self-induction), 
and round it, a secondary coil wound over the helix 
giving very conspicuous effects. D, D', in the figure, 
represent two persons holding between them an incan- 
descent lamp L, and having their other hands con- 
nected to the terminal points of the helix, under these 


conditions the current through the lamp traverses the 
arms and trunk of the two experimenters and the lamp 
glows brightly, though they feel no shock. 

If the helix be placed in a vessel of oil, and a secon- 
dary coil be wound on a wide glass tube placed over 
the primary to prevent sparks from passing between 
primary and secondary, the arrangement is that of 
a Tesla coil. A stream of crackling sparks several 
inches long will pass between the terminals of the secon- 
dary coil, but when the body is placed in the circuit little 
or no shock is felt, but only a warm glow and a partial 
anaesthesia of the region in contact with the electrodes. 

This experiment and others of a similar nature have 
given rise to a belief that with high frequencies of 
alternation there is no danger even if large currents are 
passed through the body. 

That the current through the lamp must have been 
two amperes, as estimated by D'Arsonval, is almost 
incredible, for a current of that magnitude from any 
ordinary source of electrical currents, whether direct or 
alternating, would destroy life, and produce serious 
burns of the tissues at the points of contact. 

One suggested explanation of the incandescence of 
the lamp filament is that at very high frequencies the 
resistance of the filament is enormously increased, and 
a much smaller current at a proportionately higher 
voltage will make it glow. Another explanation given 
is that the rushes of current are very large while they 
last, but have so brief a duration that the total current 
passing in a given time is comparatively small ; this, 
however, does not explain the difficulty of the absence 
of shock. Others, again, incline to the belief that the 
energy dissipated at the lamp filament is not so much 
an electrical current as a molecular disturbance, or 


" bombardment," and that the actual current may be 
remarkably small. This is supported by the incandes- 
cence of a lamp when fixed to one electrode only of 
a high frequency coil, here the true current must be 
quite small and yet the lamp glows. 

Although it is a fact that with a high frequency 
apparatus no shock is felt when the hands are in good 
contact with the electrodes, yet if there be an air gap 
in the discharging circuit the shocks at once become 
severe, and the wider the gap the more severe are the 
shocks. This observation is not alluded to in the pub- 
lished accounts of D'Arsonval's experiments. Dr. 
Hedley has further shown that if the electrodes in 
contact with the skin are progressively diminished in 
area a point is reached with small sized electrodes, 
when a distinct sensation becomes perceived, and he 
has very rightly argued that if the rapidity of alterna- 
tion be the only factor which makes the current imper- 
ceptible, it should be as Httle felt with electrodes of 
small surface as with those of large surface. 

The progressive increase of sensory effect as the area 
of contact is diminished, suggests that the concentra- 
tion or density of the current is an important factor, 
and this again makes it probable that the total actual 
current flowing must be one of very small magnitude. 

These paradoxical effects have given rise to much 
discussion, but further investigation is necessary before 
the real explanation of them can be arrived at. 

Accounts of D'Arsonval's investigations, with illus- 
trations of the arrangements of his apparatus will be 
found in the French Electro- therapeutic Journals for 
1893 and 1894, and in the Electrical Review, March 23rd, 

The practical applications of high frequency dis- 


charges to therapeutics have been mainly developed in 
France. The current led off from the primary helix 

J c 

joining the outer coatings of the jars (fig. 64) is more 
often used than the current of a secondary helix or 


Tesla coil. The patient may be attached to one ter- 
minal of the helix while the other is joined to a plate or 
sheet of metal brought near but not attached to the 
patient. In this way the metal plate and the body of 
the patient form an arrangement like the two coats of 
a condenser, which is alternately charged and dis- 
charged as the potential at the ends of the helix rises 
and falls. The apparatus is arranged in the form of 
a couch ; the patient lies upon insulating cushions 
which separate him from the metal sheet which is fixed 
beneath. It is called the " condenser couch" or '■'lit 

Or the helix itself is made large enough to enclose 
the patient as in a cage. It may be arranged vertically 
with the patient standing within it, or horizontally, the 
patient lying down. In neither case is there any con- 
tact between cage and patient, but the currents in the 
cage or helix induce currents in the patient within ; 
this is called treatment by " auto conduction." Thirdly 
the patient may be put in direct circuit with the ends 
of the helix by ordinary wire connections, wetted 
pads, or arrangements of arm-bath or foot-bath (see 
Chap. X.). These methods, devised by D'Arsonval, 
will be found fully described and illustrated in the 
Annales d' Electrohiologie for January, 1898, in an impor- 
tant paper by Professor D'Arsonval himself, and in the 
same number will be found a paper by Oudin on the 
applications of these high frequency currents to diseases 
of the skin and mucous membranes, which gives further 
details as to operative procedure. 

The field of treatment in which high frequency cur- 
rents are especially indicated is that of diseases due to 
nutritional failure (ralentissement de nutrition) such as 
gout, rheumatism, diabetes, obesity, debility. 


The physiological effects upon which their applica- 
tion is based are the very marked increase of metabolic 
activity which has been observed in experiments with 
these currents upon men and animals, thus d'Arsonval 
reports the output of CO2 in the case of a human being 
as being raised from 17 litres to 37 litres per hour. 
Associated with this there was a considerable increase 
in the production of heat, namely from 79 calories to 
127 calories per hour, the body temperature remaining 
steady at a normal point. The amount of urea secreted 
is also raised. 

The method is essentially a method of general electri- 
fication and the results it gives are somewhat similar 
to those obtained with the static machine as already 
described or with the electric bath, which will be de- 
scribed later. Each of these methods has its special 
advocates but the selection of one or other for use will 
depend a good deal upon the resources of the individual 
medical man. Thus one will have special conveniences 
for an electric bath, another will find a static machine 
more suitable and so on : good work can be done by all 
the modes of general electrification, and the high fre- 
quency methods of D'Arsonval have not as yet been 
shown to possess any conspicuous advantages over the 
others, as far as general electrification is concerned, 
though they may have certain special advantages for 
local applications, as in skin diseases. In Chapter IX. 
the subject of general electrification is considered at 
some length. 



The resistance of the body. Diffusion of current in the body. The 
action of electrical currents on living tissues. The motor nerves 
and muscles. Unstriped muscle. Sensory nerves. Refreshing 
action. Trophic effects. Electrical osmosis. Lethal effects. 

III. The resistance of the body. — The body is a 
conductor exactly in the same way as saHne solutions 
or moist sponges are conductors, that is to say, it is an 
electrolyte, and the tissues between the electrodes dur- 
ing the passage of a current are in exactly the condition 
of the liquids in an electrolytic cell, consequently the 
passage" of the current causes the accumulation at the 
positive electrode of acids, chiefly hydrochloric, from 
the abundance of sodium chloride in the juices of the 
body, and of bases, chiefly soda from the same reason, 
at the negative electrode. The region between the 
poles shows no evidences of either free acid or free 
alkali, and yet we feel sure that exchanges must be 
taking place all through the chains of molecules be- 
tween anode and kathode. Moreover, it is not reason- 
able to assume that the changes only occur in the fluids 
of the intercellular spaces, for they must also go on in 
the whole of the cell substance which is traversed by 
the current. 

Dr. Stone, ^■'' in a careful study of the resistance of the 
human body, arrived at the figure of one thousand 
* Lumleian Lectures, 1886. 


ohms as the average resistance from foot to hand, and 
from foot to foot, when the contacts were made through 
large vessels of salt water into which the extremities 
were plunged. In this way he thought he had suc- 
ceeded in eliminating the resistance of the skin, and 
considered that the figures obtained indicated the 
resistance of the deeper tissues only. 

Professor G. Weiss'-*' measuring the resistances from 
hand to hand with contacts made through bowls of salt 
water, found the average resistance in sixteen men to 
be a little over thirteen hundred ohms, and in seven 
women fifteen hundred ohms ; the reason why the latter 
showed a higher figure is not very clear, particularly as 
the skin of women is generally believed to be more thin 
and delicate than that of men. It may have been due 
to the smaller immersed area in the case of the women, 
or perhaps to a lesser number of sweat glands and hair 
follicles ; the difi"erence, however, is not great, and 
would probably be less apparent if a larger number of 
cases had been measured. 

In some measurements made in the post-7nortem room 
at St. Bartholomew's Hospital, the resistance of the 
tissues, not including the skin, was found to range 
between two hundred and four hundred ohms, w^ith 
average sized medical electrodes for the contacts. 

Different observers have given the most widely diver- 
gent figures for the body resistance, the range being 
from one thousand to two hundred thousand ohms, 
according to the nature of the contacts used in the 
experiments. The human epidermis, when dry, offers 
a very high resistance indeed, especially if it be at all 
thick and horny like that of the palms of the hands and 
the soles of the feet. When moistened and permeated 
* Arch, d^electricite tnedicale, 1893. 


with water or salt solution, its resistance becomes much 
less ; the internal tissues of the body have a compara- 
tively low resistance, and the only value of most of the 
experimental determinations of resistance is that they 
show how enormously the resistance of the skin may 
vary. The resistance offered by any patient depends 
upon the following points: — First, the state of the skin, 
whether thick or thin, dry or moist, cold or warm. 
Second, the area of the electrodes and the efficiency with 
which they are brought into contact with the surface of 
the body. Third, the electromotive force of the battery 
used in the test ; and fourth, the duration of the test. 
With low electromotive forces, one volt for instance, the 
resistance is much greater than with higher voltages, 
and polarisation becoming set up at the surface of the 
electrodes tends to make the apparent resistance even 
greater than it really is. With higher voltages the 
passage of the current produces at first an increased 
vascularity of the skin under the electrodes with 
diminution of the resistance, and if the current be 
continued, so as to cause the skin to be gradually 
destroyed, the resistance is further diminished. 

During the progress of treatment the number of cells 
in circuit must be reduced gradually to compensate for 
the fall in resistance, if this is not done there is a risk 
lest the current should rise to too high a figure, and 
injury may result to the patient from want of attention. 
Burns of the skin are sometimes produced in this way. 

The resistance of a patient is almost entirely a re- 
sistance at the contact of the electrodes with the skin, 
it can be varied in many ways, and it does vary from 
day to day in the same patient. As for the resistance 
of the tissues beneath the skin, it is a matter of a few 
hundred ohms. Careful measurements of the resistance 



of patients, and statements as to the degree of resistance 
in different morbid states cannot therefore be of much 
value or importance. 

When the electrodes are applied to mucous surfaces, 
or are in the form of needles thrust through the skin, 
the resistances are much lower. With needles of both 
poles inserted into a naevus, the resistance may be as 
low as a hundred ohms, and it is said that with needles 
in an aneurysmal sac readings as low as ten ohms have 
been recorded. 

The medical practitioner is concerned with the re- 
sistance of the body mainly as it affects the question of 
treatment, and the number of cells required to drive the 
proper current through the patient. Under conditions 
of medical practice, and using moistened electrodes, the 
resistance of the body, when the skin is well wetted 
w^ith warm water, is about two or three thousand ohms, 
that is to say an electromotive force of twelve volts 
(eight Leclanche cells) will pass a current of four to six 
milliamperes. If one electrode is placed on the palm of 
the hands the resistance will be at least double. Diffi- 
culties in testing muscle sometimes occur from not 
remembering this point, for an electromotive force with 
which contractions are easily set up in the muscles of 
the forearm and of the back of the hand, may produce 
no effect at all when the testing electrode is transferred 
to the palm. A glance at the galvanometer will, how- 
ever, show the reason why, by indicating a smaller 
current and a greatly increased resistance. 

An excessive resistance is sometimes offered by the 
dry skin (and accumulated epidermal cells) of patients 
who have been long confined in bed, especially when 
there has been little or no perspiration for some time, 
and this occasionally presents a considerable obstacle 


to the electrical examination of the muscles of such 
patients, and unless care is taken it is apt to mislead. 

During the treatment of a patient the resistance of 
his body may be calculated by Ohm's law from the 
galvanometer reading, and the electromotive force of 
the cells, if that be known. For example, with twelve 
Leclanche cells in good order the electromotive force 
will be eighteen volts, and if the current through the 
patient be four milliamperes the resistance may be 

taken as follows : — R = -^, E = i8 volts, C = -oo4 ampere, 

therefore R = or 4500 ohms. In this way an estimate 

quite close enough for most cases can readily be formed. 
When exact measurements are required a Wheatstone's 
bridge arrangement, with a battery current and a gal- 
vanometer, or with an alternating current and a tele- 
phone _(Kohlrausch's method), must be employed (see 
references given in § 32, or Kempe's Handbook of Elec- 
trical Testing). The latter method has been preferred, 
because it eliminates the difficulty of polarisation, but 
this has probably been over estimated, and the tele- 
phone method introduces other difficulties of its own. 
Professor Weiss' paper''' indicates a method of over- 
coming the difficulties of polarisation, when the battery 
and galvanometer method is used. 

112. Diffusion of current in the body. — The 
density of the current (§ 34) and the diffusion of the 
current as it passes through the tissues from one 
electrode to the other, have an important influence 
upon the results produced. It has already been stated 
that in large and heterogeneous conductors, like the 
human body, the current spreads out in sheets as it 
* Loc. cit. 

O 2 


passes from anode to kathode. Dr. De Watteville has 
very clearly illustrated this as follows: — He says: "The 
reader may picture to himself the electrical density at 
any point of a circuit of variable diameter by repre- 
senting the strength of a given current flowing through 
it by a certain number of lines. These lines expand in 
the wider portions of the circuit owing to the diffusion, 
and become crowded together in the narrower parts. 
A crowd issuing through a narrower door, and through 
gradually expanding passages, and finally reaching the 
street, like electricity flowing through a circuit of vari- 
able diameter, is said to be densest at the narrow exit, 
and it thins out, and has a lower density as it reaches 
the wider outlets." 

The path of a current between two electrodes placed 
upon the body surface is not to be marked out simply 
by drawing direct lines from the one to the other, for 
the whole of the conducting tissues between the elec- 
trodes help to provide a passage for the current, which 
spreads out from beneath the positive electrode, be- 
coming less and less dense as it occupies a wider and 
wider sectional area of the conductor, and again grows 
denser as its lines of passage become once more gathered 
together to reach the negative electrode. 

Fig. 65 shows the divergence of the directions of these 
lines of current as they pass from a positive electrode 
placed upon the back of the arm to reach the negative 
electrode placed somewhere upon the trunk, and it very 
well illustrates the fact that the current is not confined 
to the space directly between the electrodes, for some of 
the lines which indicate its direction, actually commence 
their course by curving downwards through the tissues 
below the electrode. 

It follows that parts of the body which are outside 



the direct line of the r^lectrodes may be influenced by 
the current passing between the electrodes, and it will 
be seen from the chapters on treatment that this may 
sometimes be advantageous, and sometimes the reverse. 
It also follows that the size of the electrodes is of 
importance in treatment, for at the surface of contact of 
a small electrode the density of current per unit of sur- 
face, when a definite quantity of current is flowing, will 


-Lines of current diffusion round an electrode. 

be greater than when large electrodes are used ; this 
point has been already alluded to in § 79, and will be 
again referred to later. 

113. The sensation of shock. — The effect of 
electric currents upon the nervous system seems to 
depend partly upon the magnitude of the current, and 
partly upon the rate of change in this magnitude. It is 
possible to tolerate the gradual introduction or the 
steady passage of twenty or thirty milliamperes through 


the body if the contacts with the skin at the electrodes 
are large and good, but the sensation of shock is severe, 
if currents of five milliamperes are rapidly set up in the 
body ; and when the current is broken rapidly its 
sudden cessation also produces a far greater impression 
than that felt while it is running steadily. This shock 
at the break or opening of the circuit is difficult of 
explanation, and nothing comparable to it is observed 
with inanimate electrical circuits or apparatus, for it is 
not of the nature of an induction effect ; the explana- 
tion which is offered in physiological textbooks, namely, 
that a sudden fall of potential is an effective stimulus 
to a nerve fibre is no explanation at all. 

The important part played by the rate of chang-e of 
current in producing physiological effects is clearly 
shown by what has just been said of the current slowly 
or suddenly made and broken through a circuit which 
includes the body ; the part played by the quantity of 
current passing is seen by a comparison of the effects 
of a spark drawn from the prime conductor of an 
electrical machine with that from a Leyden jar dis- 
charge. A spark a quarter of an inch long taken from 
the former produces only a slight impression, but a 
spark of the same length from the jar gives a violent 
shock. The difference between the two is largely a 
difference in quantity of current passing. In both cases 
the electromotive force is very high, and the total 
quantity is small ; but, in the case of the Leyden jar, 
there is, for the extremely brief instant of the discharge, 
a fairly large current, because of its capacity as a 

114. Electrical phenomena of nerve and muscle. 
— Nerve acts as a conductor, whether it be alive or 
dead, but there is a peculiarity in its conductivity 


which is unhke that of saHne solution, viz., its resist- 
ance in any direction does not depend solely upon its 
sectional area as would be the case in homogeneous 
conductors, but it conducts more readily along the 
length of its fibres than across them, and the same 
peculiarity is also found in muscle and in wood.'"'-' 
Brenner has shown that in nerve the transverse resist- 
ance is as 5 : I, and in muscle as of 9 : i, as compared 
with their longitudinal resistances. It is probable that 
these differences in resistance simply signify that as 
conductors they are not homogeneous. Crushed nerve 
is also said to be a better conductor than fresh un- 
damaged nerve. 

Electrical currents in nerve and muscle. 

a. Current of rest. — If the wires of a sensitive galvano- 
meter be attached to two points in a removed portion 
of either nerve or muscle, the existence of a current will 
be made manifest by the deflection of the galvanometer 
needle, its direction being that which indicates a current 
passing through the wire from the central part of the 
piece of nerve to its extremities ; this current is called 
the current of vest. It is more easily demonstrated in an 
excised and therefore damaged portion of nerve or 
muscle than in a part which is still lying uncut in the 
body ; and indeed it is probable that this current of 
rest only exists in damaged tissue, and is not present 
in normal parts at all, but that it is set up by chemical 
changes resulting from the injury. 

h. Current of action. — If while the galvanometer is 
attached to it, the nerve or muscle be stimulated in 
any way, whether by electrical, mechanical, chemical, 

* This may well be compared with the phenomena of the conduc- 
tion of heat in wood, which takes place at a different rate according 
to the direction of the grain of the wood. 


thermal, or any other means, then the galvanometer 
needle will give evidence of the production of an elec- 
trical current by a momentary deflection in the opposite 
direction to that produced by the current of rest ; this 
has been called the negative vanation of the current, or 
the current of action. It is propagated in both directions 
from the point stimulated, and travels in nerve at the 
rate of 28 metres per second, and in muscle at three 
metres per second, that is to say, the disturbance of 
equilibrium producing the current moves at these 
speeds, which are very much slower than the rate at 
which an electrical current travels along a nerve, which 
is an entirely different thing. The impulse which 
passes along a nerve to cause muscular contractions 
or sensory impressions is not an electrical impulse, 
although there is an electrical change associated with 
it. If a nervous impulse were simply an electrical 
current it should be transmissible by an electrical con- 
ductor, as for instance a copper wire, but it is not so 
transmitted, neither will a piece of damaged nerve 
convey a nervous impulse, although it may readily 
convey an electrical current, moreover, the velocity of 
an electrical current in a conductor, such as a nerve 
trunk, is immensely more rapid than the velocity of a 
nervous impulse in a nerve trunk. Hitherto the current 
of action has not been made use of for diagnostic or 
therapeutic purposes. 

115. Electrotonus. — During the passage of a con- 
stant current along a nerve certain alterations in the 
irritability of the nerve, and certain alterations in its 
conductivity are produced, this altered state is known 
under the name of electrotomis. Electrotonus then is the 
condition of a nerve during the passage through it of a 
constant current, but the effects in that part of the 


nerve near the anode are not the same as those near 
the kathode, thus there is one altered state round the 
anode or anelectvotomis and another different altered 
state round the kathode or kathelectrotomts. 

a. Aneiedrotonus. — In the region of the anode the 
irritability of the nerve is diminished, the fall in irrita- 
bility taking place at the moment when the circuit is 
closed, and remaining diminished till the circuit is 
again opened, when there is a return to the normal. 
Also the conductivity of the nerve for nervous impulses 
becomes diminished by the development round the 
anode of a resisting area through which nerve impulses 
pass only with difficulty. 

b. Kathelectrotomts. — Round the kathode the closure of 
the circuit causes a rise of irritability which is maintained 
during the passage of the current, and returns to the 
normal level when the current has ceased to flow. The 
sudden rise of irritability at the kathode on closure is a 
stimulus to the nerve, and so also in a less degree is 
the rise from a diminished irritability to the normal at 
the anode on opening. The importance of electrotonus 
partly lies in the explanation which it affords us of the 
behaviour of muscle towards constant currents, at their 
make (closure) and break (opening). Electrotonus is 
also useful medically in giving us a clue to the treat- 
ment of disease, accordingly where it is wished to 
increase the irritability of a part the condition of 
kathelectrotonus should be set up by applications of 
the kathode, and conversely the application of the anode 
is to be preferred for inducing a state of diminished 
excitability, and so of relieving pain and spasm. 

ii6. Ascending and descending currents. — 
When the electrodes are so placed that a line drawn 
from the positive to the negative poles runs in a direc- 


tion from centre to periphery, the current may be 
spoken of as a " descending current," and conversely 
it may be called an " ascending current," when the 
anode is more remote and the kathode more central. 

In the case of a nerve trunk which has been exposed 
and isolated, the conditions are different from those 
which exist in the case of a nerve which is being tested 
in situ, surrounded by other conducting tissues. In 
fig. 65 the lines of flow of current round an electrode 
are shown, and it is clear that they are not all parallel 
to one another, and that they traverse the nerve trunk 
in many different directions. 

For this reason, it is now more usual to define an 
electrical application, not by speaking of the ascending 
or descending direction of the current, but by reference 
to the sign of the pole which is used as the active 
electrode, and inasmuch as the indifferent electrode is 
commonly applied to the trunk while the active elec- 
trode is applied to a limb, the current would usually be 
a descending current w^hen the active electrode was 
negative, and ascending when the active electrode was 

The expressions "ascending" and "descending" 
current convey the idea that the direction of the flow 
in the interpolar region is of importance, while the 
phrases " the use of the negative pole," "the applica- 
tion of the anode," and so on, need not necessarily be 
taken to do more than signify the polarity of the 
electrode applied to the affected part. 

Reference to fig. 65 not only shows that the lines of 
flow are in all directions, but that the current in 
traversing any particular point must leave it with a 
polarity opposite to that with which it enters it, for 
example, the nerve trunk represented in the figure as 


traversed by the current is negative to the parts which 
He nearer to the electrode, and is positive to those 
v^hich are further away. All that can fairly be said ot 
the region surrounding the positive electrode is that it 
is positive to areas which are more remote. 

117. Reactions of nerve and muscle. — a. Battery 
cuvvents. — The phenomena of the contraction of muscles 
when their motor nerves are stimulated by electrical 
currents are as follows : — If the indifferent electrode be 
placed upon any convenient part of the surface of the 
body, and the active electrode be then applied over a 
motor nerve, it will be found that with a current of one 
milliampere from a battery, muscular contractions begin 
to be produced as the circuit is closed, and with some- 
what stronger currents contractions appear both at 
closure and at opening. With the active electrode 
negative the contraction at make or closure is easier to 
produce than when it is positive. The order in which 
they appear are : — 

a. Kathodal closing contraction (KCC). 

h. Anodal „ „ (ACC). 

c. Anodal opening contraction (AOC). 

d. Kathodal „ „ (KOC). 

The symbols affixed are commonly used for con- 
venience to designate the contractions, of these h and 
c require about twice, while d requires four times the 
current necessary to produce a. 

The exact current needed to produce contractions 
varies with the excitability of the nerves, and with their 
position, a nerve which is superficially situated requires 
a smaller current than a deep seated one, because it 
receives a greater fraction of the current, as in the 
latter case the current is more diffused before it reaches 
the nerve, so that only a part of the current indicated 


by the galvanometer is effective. For the same reason 
a patient with a thick layer of subcutaneous fat requires 
a larger current to affect his nerves than is the case with 
a lean person in whom the electrode can be brought 
into close proximity to the nerve to be tested. The 
electrode should be small in these experiments, as this 
allows us to concentrate the current more effectually 
upon the nerve. There is probably not very much 
difference in the irritability in different nerve trunks, 
but perhaps the facial nerve may be slightly more 
irritable than the others. At least the facial muscles 
can be thrown into contraction by smaller currents 
than those of the trunk and limbs, and when they 
are to be tested it is well to bear this in mind and 
so to save the patient some discomfort. 

Dr. Verhoogen*-'"^ gives the following figures for the 
contractions produced by stimulating the ulnar nerve 
at the back of the internal condyle of the humerus. 
KCC 2 milliamperes. 
ACC 3 
AOC 3-5 „ 
KOC 15 
And these may be taken as representing very well the 
approximate magnitudes of current necessary to evoke 
the contractions of healthy muscles through their motor 
nerve trunks. 

These figures are of value because they give the 
actual effects observed in a particular case, but they 
seem to be rather high, other observers have found one 
milliampere to be a sufficient magnitude of current 
for producing the minimal KCC contraction in super- 
ficially placed nerves. 

It will be seen in the next chapter that it is con- 

* Revue 'uiternationale d'clcctrotJicrapie, September, 1S94. 


venient to make use of certain nerve trunks which can 
easily be reached when the irritabihty of the motor 
nerves is to be tested. Those generally used for the 
purpose are the frontal branch of the facial nerve, the 
spinal accessory in the neck, the ulnar, and the pero- 
neal ; a standard size of electrode should also be used, 
and a disc three-quarters of an inch in diameter (about 
three square centimetres) is a suitable one. 

In a normal muscle the effect of direct stimulation of 
its fibres is concealed by the effect produced upon it 
through its nerves, for the intramuscular branches of its 
nerve both receive the impression better, and transmit 
it to all parts of the muscle more rapidly than the 
muscle fibres could do it by themselves if no nerves 
were present. Still muscle per se is irritable and capable 
of responding to stimuli by a contraction ; but for this 
it is necessary that the stimulus should have a certain 
minimum duration, rather longer than the minimum for 
a nerve trunk, accordingly it oftens happens that a 
muscle whose nerves have undergone injury may not 
respond to the rapid stimuli of induction currents, 
while they will still respond to the constant current 
slowly interrupted (see following chapter, " Reaction 
of Degeneration "). 

The contractions produced in muscle by the stimulus 
of the make and break of a constant current are 
momentary single contractions, and between the con- 
traction at make and the contraction at break the 
muscle is quiescent and relaxed, although the current 
is traversing it. With strong currents of ten milli- 
amperes or more a condition of imperfect tetanus is 
produced, which has been named duration tetanus. 
Anodal duration tetanus, ADT, is less common than 
kathodal, KDT. The duration tetanus is not usually 


seen in electrical testing, but in certain altered condi- 
tions it is more readily elicited than in health, and it 
will be considered in the next chapter. 

If the makes and breaks of a battery current follow 
one another in rapid succession, the muscle passes into 
a state of tetanus or permanent contraction ; provided 
the individual shocks succeed one another at the rate of 
twenty per second or upwards. 

b. Induction coil ctirrents. — As the discharge from an 
induction coil consists of a series of impulses or waves 
of current, unidirectional in the primary, § 72, but 
alternating in the secondary coil, and occurring about 
fifty times a second, it is reasonable to expect that their 
effect upon a motor nerve would be to throw the 
muscles into a tetanic contraction, and that is what is 
observed. If the apparatus be arranged to give single 
shocks, single contractions follow, exactly like those at 
the make and break of a battery current, in fact, each 
wave of current from a coil may be regarded as a make 
followed immediately by a break, the two contractions 
being fused by the comparative slowness of a muscular 
contraction, which occupies one-tenth of a second. 
The rise and fall of the wave with the coil are less 
sudden than the rise or fall when a battery current is 
made or broken. The opposite of this is frequently 
asserted, but it is not correct, for the current from a 
battery both rises to its full value and falls again 
instantaneously, while the rise and fall of a current 
from a coil is gradual, as shown by figs. 35 and 36, and 
may occupy a period of one-hundredth of a second. It 
has already been said that the effect upon the muscle 
is the same whether the stimulus be applied through 
the motor nerve trunk, or through the muscle itself. 
Under conditions of health, stimuli to the muscle are 


really stimuli through the motor nerves of the muscle. 
In electrical testing it is usual to apply the electrodes 
to the muscles directly ; the individual behaviour of the 
muscles is then more clearly seen than if they be 
thrown into contraction in groups through a common 
motor nerve trunk. 

When an animal has been poisoned by curare, the 
nerves are paralysed, and stimuli applied to the muscle 
still produce contractions, though stimuli to the nerve 
trunks do not. Under these circumstances the muscle 
reacts both to induction coil currents and to battery 
currents, but the contraction produced by an electric 
shock is more sluggish than in a healthy muscle. It 
is not certain, however, that curare may not of itself 
alter the character of a muscular contraction, at least 
we are not justified in supposing that this drug permits 
of a complete distinction between the effect of electric 
shocks _on nerve and on muscle. After section and 
degeneration of the nerve trunk the character of the 
muscle contraction becomes altered, as will be seen in 
the next chapter, but here too the alteration may be 
due to changes in the muscle as well as to the change 
in the nerve. 

118. Unstriped muscle. — The effect of electrical 
stimulation upon unstriated muscle is not so sharply 
defined as with striped muscle. The general effect is 
that stimuli from either the continuous current, or the 
induction coil will set up a wave-like contraction, which 
is slow and sluggish, and tends to spread for a consider- 
able distance from the point stimulated. The most 
effective method of setting up contractions in unstriped 
muscle appears to be by means of battery currents 
interrupted slowly. A long and careful account of the 
action of electricity upon unstriped muscle will be found 


in Onimus and Le Gros/-' based upon experiments on 
animals, but the conclusions arrived at are a little com- 
plicated and difficult to follow. They state that when 
peristalsis is present it may be arrested by an ascending, 
and quickened by a descending current ; they also 
noticed that arrest of movement may occur in the 
region betw^een the poles, together with contraction at 
the seat of the electrodes. 

iig. Heart muscle. — The habits of heart muscle 
are peculiar in their highly developed tendency to 
rhythmic contractions ; electric stimulation tends to 
strengthen the action of heart muscle if it be timed 
to suit the natural rate of the rhythm ; if the stimu- 
lation does not quite keep time with the heart beat it 
may effect a gradual change in its rate, until the heart 
may be brought to beat in time with the rate of the 
stimulation. If the stimulation be quite out of step 
with the rhythm of the heart it will tend to embarrass 
its action. A weak or moderate continuous current or 
a smooth unbroken succession of induction coil shocks 
may strengthen or accelerate the beat of the heart. 
Strong continuous currents destroy the rhythm of the 
heart, and cause it to stop in diastole, see below, § 126, 
and strong shocks from an induction coil do the same. 
The useful employment of electricity to strengthen a 
heart which has suddenly developed signs of failure is 
very difficult, and their is considerable risk of doing the 
patient more harm than good by injudicious electrifica- 

120. Sensory nerves. — Just as the electrical stimu- 

tion of motor nerves causes muscular contractions, so 

the stimulation of sensory nerves produces sensations. 

Accordingly, when an ordinary mixed nerve trunk is 

* " Traite d'eleciricite medicale," Paris, 188S. 


Stimulated, its motor fibres set up contractions in the 
muscles supplied by it, and its sensory fibres convey to 
the brain of the patient experimented upon a peculiar 
sensation or shock, strong or weak, in proportion as the 
current is strong or weak. The peculiarity of the sen- 
sation also produces a mental effect, so that different 
patients appear to vary in their susceptibility to these 
sensations, thus it is said that if a current be trans- 
mitted from hand to hand through a line of people, 
some will say they felt the shock severely, and some 
only slightly. 

a. The battery current. — In the case of the constant 
current, there is a sensation not only at closure and 
opening, but also during its steady passage, if the cur- 
rent be fairly strong, but not if it be weak. 

The sensations are more perceptible at the kathode 
than at the anode, but a good deal depends upon the 
relative- sizes of the electrodes; if one be much smaller 
than the other, then the greater density of current at 
the smaller one increases the cutaneous sensations there. 
If the electrodes be held still in one place, other sensa- 
tions of a burning character soon become felt, and are 
accompanied by reddening, urticaria, or blistering of 
the surface, these changes and the burning pain are due 
to the formation of products of electrolysis. In the 
removal of hairs by electrolysis, the fine needle-like 
electrode introduced into the hair follicle feels much 
as though it were very hot. The nature of the surface 
of the electrode also modifies the sensation ; and the 
current is less painful when the electrodes are firmly 
pressed upon the surface, because the contact is then 
better and the current is distributed over more points of 

Bare metal electrodes applied to the skin produce 



injury to its surface more quickly than do those covered 
with a layer of moistened wash-leather, or flannel, or 
the like, because in the former case the products of 
electrolysis are set free at the actual surface of the skin, 
while in the latter they are formed chiefly in the moist 
material which covers the electrode. With battery 
currents care must be taken to protect the skin from all 
accidental contacts with bare metal. 

h. Induction coil currents. — A single discharge from an 
induction coil produces a sensation like that of a sudden 
make or break of a battery current, the severity of the 
shock depending upon the electromotive force and cur- 
rent in the circuit. An induction coil with its contact- 
breaker in action, produces a series of shocks in which 
the individual impulses may be perceived, unless they 
follow one another too rapidly. 

At fifty interruptions per second the sensations begin 
to become fused, and at higher rates of vibration the 
sensation feels more smooth or continuous than before. 
With rapid vibration, one hundred per second and up- 
wards, a benumbing efl"ect becomes noticeable in the 
area of distribution of a cutaneous sensory nerve, if the 
electrode be applied to a point upon its trunk ; this sen- 
sation of numbness being in addition to the effect felt in 
the place of contact of the electrode. With a small 
movement of the electrode away from the nerve trunk 
the numb feeling may disappear. The numbness is 
a true anaesthesia, both tactile sensations and the 
perception of painful impressions being very greatly 
blunted, and a glow accompanied by perspiration often 
succeeds, when the current is cut off". 

When an electrode is moved over the surface of the 
skin systematically, the position of the cutaneous nerves 
can often be exactly localised by using a very small 


electrode and a current which can just be felt, for when- 
ever the electrode comes close over a sensory nerve 
trunk the sensation at once becomes quite strongly felt ; 
from this it appears that a nerve trunk is more sensitive 
to the stimulation than the nerve endings are. In test- 
ing muscles it is of advantage to know the position of 
these "sensory points," in order to avoid them and save 
the patient from unnecessary pain. On the dorsum of 
the foot there are several, which are apt to become pain- 
fully stimulated when testing the electrical reactions of 
the interosseal muscles. A little exploration of one's 
own cutaneous surface affords the best way of learning 
the position of these superficial nerve trunks. 

It is stated by Erb that the perception of the induc- 
tion coil current is a function similar to the perception 
of painful sensations, rather than of tactile. This can 
be clearly seen in patients who have analgesia, without 
loss of t-actile sensibility. This was very well illustrated 
in a case which recently came under my notice, the 
patient who could feel the touch of the electrode quite 
well, felt no shock at all even with very strong currents, 
and she was also unable to feel painful sensations when 
tested in other ways over the affected area.* 

Perhaps the word " shock " should really be confined 
to those forms of electrical sensation in which there is 
muscular contraction, for the muscular sensation con- 
tributes largely to the peculiar feeling connoted by the 
word shock. 

121. Nerves of special sense. — The nerves of 
special sense respond to electrical stimulation by their 
own special sensations, thus stimulation of the olfactory 

* For a minute analysis of all the phenomena of electrical sensi- 
bility see Bordier, " Sur la sensibilite electrique de la peau," Paris, 

P 2 


nerve produces a smell " like phosphorus," and stimu- 
lation of the optic nerve produces the impression of a 
flash of light. The optic nerve seems to be remarkably 
sensitive to small electrical currents, and the sensation 
of a flash of light is very easily produced by the small 
current obtained from a silver coin and piece of zinc 
put into the mouth, between the gums and cheek. 
When the metals are made to touch, the optical effect 
is distinct. Some observers have even thought that 
the colour of the flash seemed to depend upon the direc- 
tion of the current, and that the kathodal closure gave 
a reddish colour and anodal closure a bluish one. These 
effects can be fully studied by a battery of four or five 
elements, with one pole at the nape of the neck and the 
other over the temple or eyelids. The accident which 
befell Duchenne, who applied a current of unknown 
strength to a patient's face, and apparently caused very 
serious damage to the sight of one of his patient's eyes, 
described at length in Electrisation localisee, 3rd edition, 
p. 15, may have been a retinal haemorrhage due in- 
directly to the electrical application. 

The auditory nerve. — This nerve also can be made to 
respond to galvanic stimulation. It is not so very easy 
in healthy individuals to produce the electrical reactions 
of the auditory nerve, for fairly strong currents are re- 
quired, and some of the effects upon the eyes and brain 
make the experiment unpleasant ; but the investigation 
is important, because of its bearing upon the treatment 
of tinnitus auriuni, as the prognosis in any particular case 
turns largely upon the way in which the auditory nerve 
reacts. There is a close likeness between the formula 
of the auditory nerve and that of the other nerves. 
The kathodal closure produces a sensation of sound, 
which may continue during the passage of the current, 


but the anodal closure does not ; on the other hand the 
anodal opening produces a sound and kathodal opening 
does not. The formula then is : — 

KC sound. 

KD sound. 

KO — 

AC — 

AD — 

AO weak sound. 
These auditory phenomena will be again referred to 
in a later chapter. 

Galvanic stimulation of the nerves of taste is easily 
produced, and the simple experiment just mentioned 
for producing the optical sensation of a flash of light 
will at the same time produce a metallic taste, and by 
passing a current from one pole at the back of the neck 
to the other below the chin over the hyoid bone, the 
same metallic taste is produced. 

122. Other org^ans. — Besides the physiological action 
of electricity upon muscle and nerve, it has an action on 
secreting glands, upon the circulation, and upon the 
brain. It is quite in accordance with what one would 
naturally expect that a current passing through a secret- 
ing gland or through its secretory nerves should cause 
increased secretion ; and that a current passing through 
a viscus containing unstriped muscle should cause peri- 
staltic contractions of that viscus, and there is no need 
for us to enter into detail at present by describing the 
particular behaviour of the uterus, of the bladder, or of 
the intestine, for these points will be better treated of 
later. (For vaso-motor effects see § 146). 

In the case of the brain experimental physiologists 
have made much use of electrical stimuli in determining 
the situation of motor centres in the exposed cerebral 


cortex. When a continuous current is passed trans- 
versely through the skull, with the electrodes on the 
temples or mastoid processes, there is a disturbance of 
equilibrium, a feeling of giddiness, or an actual un- 
steadiness, with a tendency to fall towards the side of 
the anode, and sometimes there is conjugate deviation 
of the eyes to the side of the kathode, with a kind of 
oscillation or lateral nystagmus. 

It has been supposed that the disturbance of equili- 
brium depends upon a state of kathelectrotonus of one 
hemisphere with anelectrotonus of the other; the former 
hemisphere being in a state of exalted excitability and 
the latter in a state of diminished excitability, their 
action is no longer balanced, and a sensation of giddi- 
ness is the result. 

The brain is not easily influenced by induction coil 
currents applied to the outside of the skull, though 
responding readily when the electrodes are applied 
directly to its substance, but this is only because the 
currents of the required strength are so painful to the 
skin as to be badly borne. It is incorrect to suppose 
that the brain or the spinal cord are protected from 
electrical currents by their bony coverings. 

123. The "refreshing action'' of the galvanic 
current. — Dr. G. V. Poore^--' has reported some re- 
markable experiments upon what has been called by 
Heidenhain "the refreshing action" of the constant 
current ; he investigated the fatigue of muscles pro- 
duced when a weight is held out steadily at arm's 
length, and gives an instance of a patient who was able 
to hold out his arm horizontally with a weight of seven- 
teen ounces in the palm for a period of four minutes, 

* " Electricity in Medicine and Surgery," Dr. G. V. Poore, 
London, 1876. . 


and then complained of great pain in the muscles and 
fatigue, and declared his inability to go on but was 
relieved of his pain at once by the passage of a con- 
stant current in a descending direction along the arm. 
Another person was then experimented on in the same 
way ; after holding out the weight at arm's length 
for seventy seconds, he felt pain and fatigue, but the 
application of the current at once removed both, and he 
continued to support the weight for five minutes and a 
quarter, and at the end of that time was willing to go 
on longer. Dr. Poore says : " similar experiments to 
these have been tried on several of the author's friends, 
and they all tend to show that the endurance of volun- 
tary muscular action is enormously increased by the 
passage of a constant current, and the feeling of fatigue 
both during and after the prolonged effort is mitigated 
or entirely obviated." 

Dr Poore also demonstrated that the force as well as 
the endurance of a muscular effort could be increased 
by a galvanic current. Eight successive squeezes with 
a dynamometer, at intervals of ten seconds, gave an 
average of 48^ pounds for each squeeze, but eight more 
squeezes with the aid of the current gave an average of 
59^ pounds, although they came ten minutes after the 
first series, and while there was distinct consciousness 
of fatigue from the first experiment. 

The current used was never strong enough to produce 
involuntary contraction of the muscles. Capriati {Arch, 
d'elect. medicale) has recently confirmed and extended 
these observations. 

124. Trophic effects. — Experiments were made by 
Dr. Beard''' to determine the effect of general faradiza- 
tion upon the growth of some puppies, they were kept 
* Beard and Rockwell, " Medical and Surgical Uses of Electricity." 


under treatment for four weeks, being treated daily with 
an induction coil current ; at the end of the time the 
two puppies which had been so treated had gained in 
weight faster and were perceptibly bigger than the 
two others, which had been kept untreated as control 
animals ; however, other experiments gave conflicting 
results. It is reasonable to expect that the metabolism 
of the tissues should be increased by the vigorous 
stimulation, and that a young animal should increase 
in size in consequence, just in the same way as massage 
of the muscles increases their size and activity. In the 
treatment of children by electricity for paralysis, a great 
improvement in their general health has been often 
noticed by myself, and general electrification applied 
to children with rickets does them much good. 

125. Electric osmosis. — The fact has been long 
known that a movement of electrolytic fluids compar- 
able to osmosis takes place in the direction of flow of 
the current, namely, from the positive to the negative 
pole; and fluid can in this way be made to pass through 
membranes or porous diaphragms against the force of 
gravity ; and it has been proposed to make use of this 
process for the introduction of drugs into the body 
through the skin. It is evident, however, that it is 
rather an elaborate method of administering a drug, 
and only in certain cases can it have any advantage 
over the methods of giving drugs by the mouth or 
hypodermically ; besides, it would be difficult to know 
when the proper quantity had passed into the system. 
It was also hoped that in this way it would be possible 
to apply drugs locally, as for instance, iodide of potas- 
sium to a gumma, but this cannot be satisfactorily 
efl'ected because the drug is carried off by the circula- 
tion quite as fast as it enters through the skin. Still, 


there is one particular object which can be well and 
conveniently secured in this way, namely, the introduc- 
tion of cocaine to produce local anaesthesia of a portion 
of the skin, this can be done very simply by covermg 
the positive electrode with a layer of absorbent cotton 
well moistened with a ten per cent, solution of pure 
cocaine in guaiacol and holding it steadily to the part, 
with five milliamperes of current the shin should become 
anaesthetic in about five minutes. The procedure is of 
value before small superficial operations, and in neural- 
gic affections. Either the pure alkaloid or its salts may 
be used as both are soluble in the guaiacol. 

Many applications of electrical osmosis or cataphore- 
sis, as it is also called, have been proposed ; among them 
is one for the treatment of gouty deposits by salts of 
lithium. The affected part is immersed in a bath of 
warm solution of lithium chloride of a strength of two 
per cent, connected with the positive pole, the circuit is 
closed by a second warm bath containing a dilute solu- 
tion of common salt in which the patient immerses 
some other indifferent part of his body. Currents of 
25 milliamperes for 20 or 30 minutes are used. Dr. 
HeyerdahP'-' has published some recent cases in which 
he carried out this treatment with good results. Dr. W.J. 
Morton of New York, has published a valuable treatise 
on the subject of cataphoresis dealing fully with its 
history, and its applications in medicine, surgery and 
dentistryf which should be consulted by those wishing 
to go deeply into the question. 

126. Death from electric shock. — The fatal effects 
of powerful currents is probably due to stoppage of the 

* "Tidsskrift for den Norske Icege forening," Kristiania, May 15, 

t " Cataphoresis or Electric Medicamental Diffusion," New York, 


action of the heart, the tracings (figs. 66, 67) show the 
results in some experiments upon cats under chloroform. 
In the first is seen the rapid fall of blood-pressure to 
zero after the passage of a current of half an ampere 
through the thorax ; while a current of the same mag- 
nitude through the skull produced a trifling effect, 
which is seen in the first part of the same tracing. In 
fig. 67 is seen the secondary effect upon respiration 



_n n_ 

ElG. 66. — Blood-pressure tracing, showing effect of electric shock through skul 
and through thorax of a. cat. 

TX^l^-fl ^ f~Yi-Trirfm%|W 

Fig. 67. — Tracing of respirations at first rapid, then slowing and stopping, after 
electric shock, and secondary to failure of the circulation. 

caused by the failure of the blood supply in the respira- 
tory centre. These tracings were taken during some 
experiments with the direct current. Oliver has more 
recently published tracings showing that with alternat- 
ing currents the results are similar. To cause death 
the current must have a certain minimal value, and 
must traverse a vital organ, the heart being the most 


- The views of D'Arsonval are that electricity proves 
fatal by primary arrest of respiration, and that the 
victims of shock can be resuscitated by artificial re- 
spiration. Prevost and Battelli have shown that 
death may be caused in either of these ways, the 
heart faiHng first in some cases and the respiration 
in others. Artificial respiration is important in the 
latter class, but of no use in the former. In the 
absence of direct observations the minimum fatal cur- 
rent for human beings may be estimated at about one 
half to one ampere. The most common path of the 
discharge is from one conductor to earth through the 
body, but the current may also pass directly from the 
body to the other conductor of the system. In the first 
case the point of exit is generally by the feet. Burns of 
the skin should always be looked for at the points of 
entry and of exit ; they may be severe or slight. When 
the current goes to earth through the feet these may 
not show signs of burning if the foot covering is damp. 
The severity of the burns is proportional to the dura- 
tion of the discharge. Most of the fatal accidents have 
been with potentials above one thousand volts. The 
body may carry a current sufficient to produce exten- 
sive burning at the points of contact, without causing 
death, this may even be the case when the current has 
fairly traversed the trunk. In a recent accident in 
London two men were concerned and the current 
passed from the conductor to the first and from him 
through the second to earth. The first man survived 
though the second was killed. The relative danger of 
alternating and direct currents is not decided ; there is 
probably no great difference. 

127. Thermal effects. — With the small currents 
used in medicine there is no appreciable . heating of the 


tissues. A slight warmth can be felt over a naevus 
during its electrolysis. In cases where death has been 
caused by the passage through the body of the powerful 
currents used for electric lighting, well marked signs of 
the production of heat have been observed post-mortem 
(see preceding paragraph). 

128. Electrical organs. — The electrical organs of 
many fishes (electric eel, torpedo) may be briefly 
noticed in this chapter. They consist of lobes of a 
honeycomb-like structure, usually developing in a simi- 
lar way to muscle, and supplied freely with nerves 
which terminate in the cells of the honeycomb in 
expansions something like those of muscle end-plates ; 
irritation of their nerves causes an electrical discharge. 
It appears that they may have become specialised and 
developed from ordinary voluntary muscle, for the sake 
of utilising the electrical current of action, and that the 
structural changes are associated with the development 
of this portion of the muscular mechanism at the 
expense of its strictly motor powers. The chemical 
examination of the electrical organs seem to show that 
the products of their activity are very similar to those 
of active muscle, CO2 and an acid reaction being pro- 

Du Bois Reymond showed long since that muscular 
contraction always yields a current which can be 
measured by a galvanometer, and Waller has lately 
shown a method of demonstrating in the human subject 
that there is an electric current produced by the heart's 
beat, and that it can be led off to a galvanometer by 
wires from the two hands. It may be that the peculiar 
powers of electric fishes have grown up from the elec- 
trical current of action common to all contracting 
muscle, but it is difficult to trace the intermediate steps 


in the scale of development. The skate has an elec- 
trical organ in its tail which is not able to give strong 
shocks, although it can deflect a galvanometer. 

129. Magnetism. — It seems to be rather doubtful 
whether any physiological effect has ever been observed 
to be due to the action of a magnet. Lord Crawford 
(then Lord Lindsay) and Mr. Cromwell F. Varley, with 
the help of an enormous electro-magnet, belonging to 
the former, were unable to perceive any sensation even 
on placing their heads between its poles. But in dis- 
cussing these experiments in an address delivered at 
the Midland Institute at Birmingham,^'"' in October, 
1883, Sir William Thomson came to the conclusion 
that it is just possible that there may be a magnetic 
sense, and indeed a committee of the Society for 
Psychical Research, f who examined a large number of 
persons by placing their heads near the poles of an 
electro-magnet, found three who were sensitive and 
were able to say when the current was on or off. One 
of these persons was examined later by Prof. W. F. 
Barrett,! who found that when he was suffering from 
neuralgic pain, it became intensified by the presence of 
a powerful magnet. 

In some recent experiments conducted with very 
powerful electro-magnets by Dr. Peterson and Mr. 
Kennelly in Edison's Laboratory, the results were 
entirely negative as the following extracts show. The 
subject placed his head between the poles of a large 
electro-magnet, which could be excited from a dynamo- 
machine. They reported as follows : — 

" The armature of a dynamo was removed, leaving a 

* Nature, vol. xxix., p. 438. 

t Proc. Soc. Psychical Research, part iii. 

\ Nature, vol. xxix., p. 476. 


space between the poles of its field magnet. This field 
magnet was then excited from another dynamo, driven 
by steam power and the subject introduced his head 
into the space between the poles. The weight of the 
electro-magnet was over 5000 pounds, and the intensity 
of the magnetic field produced within the polar cavity 
after removal of the armature, though not uniform, may 
be estimated at a mean of 2500 C.G.S. lines to the 
square centimetre. A long board was placed upon the 
base plate leading into this polar cavity, and the subject 
experimented upon lay on his back upon the board with 
his head and shoulders in the cavity between the poles, 
and exposed thus to the full influence of the magnetic 
field. A switch so nearly silent in action as to be 
inaudible to the subject was arranged to close and 
open the exciting current circuit through the field 
coils. On closing the switch nearly the full magnetic 
intensity would be active and permeating the head 
within practically one second. Similarly on opening 
the switch, almost the whole intensity would diappear 
in about one second." 

"Five men, ourselves among the number were, sub- 
jected to trial. One case described will describe all." 

" The subject lay back upon the board and concen- 
trated his attention upon his sensations. His right 
wrist was extended and was grasped by one observer, 
who took, sphygmographic tracings of the pulse. A 
second observer placed a hand on his chest to observe 
any irregularity that might occur in respiration. A 
third observer, in view of these two, but unseen by the 
subject of the experiment, opened and closed the switch 
that excited and released the field, signalling to the first 
two observers as he did so. The strong magnetic 
influence was therefore turned on or off" at will, and 


without the knowledge of the subject. Several sphyg- 
mographic tracings were taken in each of our subjects, 
and in one the knee-jerk was tested continuously." 

"The sphygmographic tracings taken during the 
seance show no change in regularity, in spite of the 
making and breaking of the enormous magnetic influ- 
ence during its registration. The respirations were 
not changed in the least. The knee-jerk also presented 
absolutely no change. As to common sensations, there 
were none that could be attributed to the magnetic 
influence, and the subject could not discover w4ien or 
whether the field had been excited. The testimony of 
all five subjects was alike." 

" No change could be seen in the circulation in the 
web of a frog's foot when this was placed between the 
poles of a large electro-magnet, and no effect was per- 
ceptible in a dog which had been confined for five hours 
in a strong magnetic field." 

Experiments were also tried with another magnetic 
arrangement, in which the magnetism was reversed 280 
times a second, as follows : — 

" A large coil of stout, cotton-covered copper wire, 
about 30 cm. high, and 25 cm. internal diameter, 
composed of nearly 2000 turns, and weighing about 70 
kilogrammes, was supported horizontally in such a 
manner that the head of the subject experimented upon 
could be freely introduced within the coil, and subjected 
to the electro-magnetic field created there by passing a 
current through the wire. The resistance of the coil 
was 10 ohms, and its inductance 073 henry. An alter- 
nating electromotive force of 1200 volts, making 140 
cycles, or 280 alternations to the second, was connected 
with this coil, the current supplied being 1-85 amperes. 
The magnetic field in the coil would thus be reversed 


280 times to the second. Each of the authors acted as 
subjects in the experiments, permitting the 1200 volt 
alternating current to be made and broken frequently 
in the huge magnetic coil surrounding his head. No 
effect whatever was experienced. The coil itself 
hummed with the current, and a strip of sheet iron 
held in the cavity of the coil, but not touching it, 
vibrated perceptibly in the hand and gave a distinct, 
loud sound, which was determined to be middle C of 
the musical scale." 

" The authors conclude that the human organism is 
in no wise appreciably affected by the most powerful 
magnets known to modern science ; that neither direct 
nor reversed magnetism exerts any perceptible influ- 
ence upon the iron contained in the blood, upon the 
circulation, upon ciliary or protoplasmic movements, 
upon sensory or motor nerves, or upon the brain."* 

It need hardly be pointed out that the phenomena of 
so-called " animal magnetism " have absolutely nothing 
to do with magnetism whatever. Moreover, the ordin- 
ary magnets used in medicine, and credited with 
wonderful powers, have a purely suggestive or psychic 
effect, and would in all probability be quite as useful if 
made of wood. 

* Read before the American Electro-Therapeutical Association, 
1892, reprinted with illustrations, in the English Electrical Review, 
August 18, 1893. 




Electrical testing. The motor points. Relation of spinal nerve- 
roots to muscles. Morbid changes in the electrical reactions. 
The reaction of degeneration. The sensory nerves. Nerves 
of the special senses. The auditory nerve. 

130. Electrical testing of nerves and muscles.— 

The examination of the electrical reactions of the mus- 
cles in cases of paralysis is a very important part of 
medical electricity. Even those who are indifferent to 
the therapeutic actions of electricity are accustomed to 
attach importance to the electrical reactions as an aid 
to diagnosis. 

An electrical test often gives distinct evidence in 
cases where without it one could only guess at the 
morbid condition of the affected parts. The following 
history affords a useful instance of its value. A patient 
had an accident with broken glass, cutting himself in 
four places ; as the ulnar nerve showed signs of injury 
the wounds were carefully examined. In two of them 
the nerve was found to be divided and was sutured. In 
the other two wounds the nerve could not be seen, and 
it was thought to have escaped injury at these points. 
No electrical test was made at the time. Some weeks 
later the patient was referred to me for examination as 
the limb remained paralysed. In my report I stated 
that the nerve had undoubtedly been divided in a third 
place, namely, in the uppermost wound, which was 
above the elbow. An operation was accordingly per- 



formed, the nerve was found to be divided and it was 
joined at that point. Some time later I saw the case 
a^ain and reported that the nerve was in process of 
repair, and wanted only time and electrical treatment 
to recover its functions. After this the patient re- 
mained for some time with but slight signs of improve- 
ment, and a further exploratory incision was made to 
put aside all doubts as to the existence of re-union of 
the nerve. At the operation the electrical testing was 
vindicated by the discovery of a proper re-union of the 
ends of the nerve. With time the patient made a good 

Electrical testing depends upon the fact that changes 
may appear in the normal reactions as a result of 
disease or injury. In the last chapter we considered 
the behaviour of normal muscle to the current of the 
induction coil, and to the make and break of a current 
from a battery of galvanic cells, and in this chapter the 
changes due to disease will be considered, together with 
the practical details of testing. As there may be 
changes in the behaviour of the muscle to both the 
coil and the cells, both forms of stimulus are used in 
the electrical examination of a muscle. The testing is 
usually a testing of the contractility of the muscles and 
the active electrode is applied to the muscle itself, at or 
near to its motor point. The nerves may also be tested 
to determine their power of conducting motor impulses, 
their conductivity being shown by the movements of the 
muscles to which they may be distributed. Sensory 
nerves are also tested and their condition inferred from 
the responses of the patient, but it is to the muscles that 
the testing electrode is generally applied as the state 
of the motor nerves is mainly deduced from the results 
shown by the muscular contractions. 


In testing a muscle the electrodes required are the 
indifferent electrode (fig. 40) and the electrode with 
"closing" key (fig. 38). The former is to be placed 
over any convenient and remote part of the body, thus 
the patient may hold it against his chest, or it may be 
sHpped down the back of the neck so as to be held in 
place by the pressure of the clothing, or, with a patient 
lying down it can be placed beneath the hips, or finally, 
if the patient is lying on his face it may be placed over 
the sacrum and held there by an assistant. In any 
case it must touch the skin with even and firm pressure 
throughout the process of testing. Both the electrodes 
and the surface of the body concerned must be well 
moistened with warm water or salt and water ; and the 
more thoroughly this is done the more satisfactory will 
the testing be Salt and water lowers the resistance of 
the skin better than plain water, but its use has the 
drawback that it shows more tendency to corrode the 
electrodes. Plain hot water is therefore the best 

In testing the intrinsic muscles of the hands and feet, 
and with a few other muscles, as for example the del- 
toid, it may be convenient to apply both electrodes to 
the skin over the part tested in such a way as to cause 
the current to pass right through the part, thus the 
interossei are very conveniently tested with the indiffer- 
ent electrode under the palm or sole and the active 
electrode on the dorsal aspect of the hand or foot. 

Again for testing the muscles of the legs a very good 
position is for the patient to lie prone, with the indiffer- 
ent electrode held by an assistant over the lumbar spine, 
the leg to be tested being flexed and supported vertically 
in the left hand. In this position all the leg muscles 
can be reached easily, and the foot is free to move in 



any direction in response to the contractions of the 
muscles as they are tested. The left hand which holds 
and supports the ankle is well placed for feeling the 
movements of the tendons. 

The active electrode or testing electrode should be of 
small surface, one which is three-quarters of an inch in 
diameter is good. 

131. The motor points. — These are points to which 
the testing electrode should be applied in order to set 
up a contraction most easily in the subjacent muscle, or 
they are points at which motor nerve trunks can be 
easily reached. They represent positions at which a 
maximum effect can be produced by a given current, 
and a good knowledge of the motor points enables one 
to carry out a test with comparatively weak currents, 
and therefore with the least amount of discomfort to 
the patient. Many diagrams of the motor points have 
been prepared, most of them being based upon Von 
Ziemssen's plates (see Plates I. to VI . at the end of this 

Von Ziemssen prepared his plates by exploration of 
the surface with a testing electrode, and marking the 
points as they were found. He found by dissections on 
the dead body that the excitable points corresponded 
to points at which the main nerve supply entered the 

It should be borne in mind that the motor points are 
not quite constant for different individuals, their exact 
place varying a little in different cases, but not so 
greatly as to diminish the value of knowing their 
positions. In actual practice the best position of the 
electrode can be readily found by experiment, by mov- 
ing it about in the neighbourhood of the usual position 
of the motor point of any particular muscle until the 


contraction shows that the exact spot has been touched. 
The ease with which the motor points can be found 
depends a great deal upon the amount of subcutaneous 
fat present, and the examination of the deeper muscles 
is much more difficult than of the superficial layer, 
indeed in the case of some of the deep muscles it is 
almost impossible to produce satisfactory evidence of 
a contraction limited to the muscle sought, for the 
diffusion of the current will throw into action the neigh- 
bouring superficial muscles and so obscure the result. 
It is very important to place the patient's limb in a good 
position, so that any muscular movement looked for 
may be readily seen ; the muscles must be lax, the limb 
should be supported by the hand of the operator, and 
not lying flat upon the table or couch. It is best to 
begin with a current which is easily able to throw 
the muscle into contraction and to apply it only for a 
very brief moment at a time, in this way the patient 
will be least worried, and the process of testing will be 
sooner over. It is well always to try the strength of 
the current on oneself before touching the patient. 

It is assumed that the action of the individual mus- 
cles is known, so that when a contraction is produced, 
it can be referred to its proper muscle. The actions of 
the muscles were elaborately studied by Duchenne, and 
he has described them at great length in his " Physio- 
logic des Mouvements." Besides watching for and see- 
ing the movement produced by the contracting muscle, 
one may often feel a weak contraction by placing the 
hand over the tendons lightly, or one may see or feel 
movements of the body of the muscle itself when they 
are too feeble to move the bone to which the muscle 
is attached. 

The subjoined table of the points at which certain 


nerves may be conveniently stimulated will be of 
service, and Plates I. to VI. which show the motor 
points must be continually referred to until they are 
known by heart. The areas of skin which are served 
by the several cutaneous nerves should also be studied. 
Heiberg's "Atlas of the Cutaneous Nerves," translated 
by Dr. Wagstaffe,'-'-' has some useful coloured outlines 
of these areas of distribution. Prof. Flower's "Atlas" 
may also be referred to. (See Plates VII. to IX., after 
Flower and Ranney). Brodie's " Dissections Illus- 
trated " is also useful. 

Points favourable for the testing of nerves : — 
In the upper limb : — • 

1. The median, along the inner border of biceps, and 
at the bend of the elbow. 

2. The ulnar, in the groove between the internal con- 
dyle and the olecranon. 

3. The musculo -spiral, at the point where it emerges 
from the triceps ; namely, on the outer side of the 
upper arm about the junction of the middle and 
lower thirds. 

4. The jmisculo -cutaneous, between the biceps and 

5. The long thoracic (serratus magnus) on the inner 
wall of the axilla. 

6. " At a spot one inch above the clavicle, and a little 
externally to the posterior border of the sterno- 
mastoid, immediately in front of the transverse 
process of the sixth cervical vertebra, a simul- 
taneous contraction can be produced in the deltoid, 
biceps, coraco-brachialis, brachialis anticus and 
supinator longus." This point has been called 

* Bailliere, Tindall and Cox. 


the siipya-claviculav point of Erb. It is a motor 
point for the fifth and sixth cervical roots before 
they reach the brachial plexus. 
In the lower limh : — 

7. The anterior crural, in the fold of the groin just 
outside the femoral artery. 

8. The sciatic, just below the gluteal fold at the back 
of the thigh. 

9. The internal popliteal nerve, in the popliteal space, 
and to the inner side of the tendo Achillis. 

10. The peroneal, just above the head of the fibula, be- 
side the biceps tendon. 

In the face: — 

11. The facial, through the cartilage of the lower 
surface of the meatus auditorius. Its chief rami- 
fications can be reached where they emerge from 
the parotid gland. Erb chooses for stimulation 
three main branches of the facial : {a) for muscles 
above palpebral aperature ; {h) for muscles in front 
of upper jaw, between the orbit and the mouth ; 
{c) for muscles of the lower jaw. He tests each of 
these in two places, first at points just in front 
of the ear, and secondly for {^a) at the temple, for 
{h) at anterior extremity of zygomatic bone near 
its lower border, for {c) at the middle of the 
inferior border of the horizontal ramus of the 
lower jaw. 

12. The fifth, at the supra-orbital foramen, at the 
infra-orbital foramen, at the foramen mentale, on 
the side of the tongue. 

In the neck : — 

13. The spinal accessory, at the top of the supra- 
clavicular triangle, where the nerve pierces the 


14. The phrenic, on the outer edge of the lower part 
of the sterno-mastoid. 

15. The hypoglossal, along the upper border of the 
great cornu of the hyoid bone. 

16. The recurrent laryngeal, along the outer border of 
the trachea. 

17. The pneumogastvic and glosso-pharyngeal along the 
track of the carotid artery just below the angle of 
the jaw. 

132. Relation of spinal nerve roots to muscles. 
— Frequently it happens that paralysis affects a group 
of muscles ; in these cases much light may be thrown 
upon the diagnosis if it is possible to trace back the 
nerve supply of the affected muscles to their spinal 
roots. This is not always easy, particularly when the 
nerve trunks pass through a plexus like the brachial 
plexus on their way from the cord to the muscles. For 
example, the distribution of a paralysis affecting some 
of the muscles of the hand might enable us to distin- 
guish between a lesion of the trunk of the median nerve 
on the one hand, and a lesion of the eighth cervical and 
first dorsal roots on the other ; in the latter case the 
whole of the thenar and hypothenar eminences and all 
the lumbricales and interossei would be involved, in 
the former case many of these muscles would escape, 
namely, the hypothenar, the interossei, the two inner 
lumbricales, the adductor pollicis, and the inner half of 
the flexor brevis, all of which are supplied by the ulnar 

A paper published in Brain, 1881, by Dr. Ferrier, 
gives a tabular statement of the more important spinal 
nerve roots, with the muscles supplied by each. As it 
is likely to be of great value in electrical diagnosis we 
reproduce it here, as modified by Dr. De Watteville, 
Lancet, July, 14, 1883. 


Nerve roots: — 

4th cervical. — Deltoid, rhomboids, spinati, biceps; bra- 
chialis anticus, supinator longus ; extensors of 
5th cervical.— Deltoid (clavicular portion), biceps; bra- 
chialis anticus, serratus magnus, supinator longus ; 
extensors of hand. 
6th cervical. — Latissimus dorsi, pectoralis major, ser- 
ratus magnus, pronators, triceps. 
7th cervical. — Teres minor, latissimus dorsi, subscapu- 

laris, pectoralis minor, flexors of hand, triceps. 
8th cervical.— Flexors of wrist and fingers, muscles of 

hand, extensors of wrist and fingers, triceps. 
1st dorsal. — Muscles of hand (thenar, hypothenar, in- 

8rd lumbar. — Ilio-psoas, sartorius, adductors, extensor 

4th lumbar — Extensor femoris et cruris ; peroneus 

longus ; adductors. 
5th lumbar. — Flexors and extensors of toes -tibial, 
sural, and peroneal muscles, extensors and rota- 
tors of thigh, hamstrings. 
1st sacral. — Calf, hamstrings, long fiexor of great toe, 

intrinsic muscles of foot. 
2nd sacral. — Intrinsic muscles of foot. 
Reference to the paper of Dr. Ferrier will show that 
in his table the function of each nerve root is expressed 
in terms of the movements produced, and not in terms 
of the muscles concerned in producing the move- 

Dr. Herringham'-'' has also tabulated as follows the 
results of numerous dissections of the brachial plexus in 
new-born infants. 

* Proc. Roy. Soc, March, 1866. 


Usual nerve supply : — 

Srd, 4th and 5th cervical. — Levator anguli scapulae. 

5th. — Rhomboids. 

5th or 5th and 6th cervical. — Supraspinatus, infraspinatus, 

teres minor. 
5th and 6th cervical. — Subscapularis, deltoid, biceps, 

brachialis anticus. 
6th cervical. — Teres major, pronator radii teres, flexor 
carpi radialis. Supinator longus and brevis. 
Superficial thenar muscles. 
5th, 6th and 7th cervical. — Serratus magnus. 
6th or 7th cervical. — Extensores carpi radiales. 
7th cervical. — Coracobrachialis, latissimus dorsi, exten- 
sors at back of forearm, outer head of triceps. 
7th and 8th cervical. — Inner head of triceps. 
7th, 8th and 1st dorsal. — Flexor sublimis and pro- 
fundus, flexor carpi ulnaris, flexor longus pollicis, 
and pronator quadratus. 
8th cervical. — Long head of triceps, hypothenar mus- 
cles, interossei, deep thenar muscles. 
The pectoralis major from 6th, 7th, 8th and ist dorsal. 
The pectoralis minor from 7th, 8th and ist dorsal. 
133. Practical testing.— When a lair degree of 
skill in finding the motor points has been acquired, the 
chief difficulties of testing the reactions of a patient's 
muscles will disappear. Nothing is so useful as to 
practice frequently upon one's own muscles, and the 
dislike which many people have to applying currents to 
their own persons is unreasonable, for a current which 
is strong enough to provoke contraction in healthy mus- 
cles is not really painful and there is no way of learning 
the motor points like a practical experiment upon one's 
own muscles. Half an hour spent in picking out one's 
own motor points, and in observing the relative sensi- 



tiveness of the skin in different parts of the body, and 
in noting the effect of a thorough moistening of the skin 
before applying the testing current will well repay a 
beginner in electrical testing. 

Another small point of importance is to make a rule 
of applying the current to one's self at the commence- 
ment of a test. If this is done the patient feels re- 
assured, and the chance of the current being applied 
too strongly is decidedly lessened. The easiest method 
is as follows : — 

Place the indifferent electrode in position on the 
patient and moisten the skin of the part to be tested, 
then grasp that part in the left hand, and, taking the 
testing electrode in the right apply it to the back of the 
left hand which is holding the patient; the current then, 
on closing the key, will pass to the patient through the 
hand of the operator, who will be able to judge of the 
strength of the current by the sensation or the muscular 
contraction produced, and will be able to adjust it 
accordingly. Always commence testing with the coil, 
and use the cells later. There is no need to push the 
coil current too greatly. In testing with the cells 
begin with about sixteen cells for the limbs, or half 
that number for the face, and apply the electrode, 
which should be made the kathode. Note whether a 
closing contraction is visible or not ; if not, increase the 
number of cells in circuit until it appears, and take 
readings of the galvanometer ; when the first closing 
contraction becomes visible note the effect of moving 
the electrode, and find the most effective spot for stimu- 
lating the muscle, then compare the A.C.C. with K.C.C., 
and take especial notice of the nature of the contraction, 
to see whether it be quick or sluggish ; compare the con- 
tractions obtained by direct stimulation of the muscle 






































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with the effects of stimulating the nerve trunks. Lastly, 
test sensation with the induction coil current, and note 
the results upon a table like that given in the accom- 
panying leaf. 

Compare the reactions of the healthy side with those 
of the affected side. 

When the affected parts can be compared with the 
corresponding region on the opposite and sound side of 
the body, it is not difficult to perceive changes in the 
electrical reactions. When the disease is bilateral this 
is not so simple, and one must depend to a certain 
extent upon previous experience, and upon comparisons 
with one's own reactions ; but, wherever possible the 
comparison of the affected muscles with their fellows of 
the opposite side of the body is a matter of the first 

134. Changes in the electrical reactions.— The 
changes which may be found in the reactions as the 
result of disease or injury are classified as follows :- — 

1. Changes in the amount or quantity of response to 
stimuli, the character or quality of the reactions not 
being otherwise changed. 

This includes simple increase of excitability and simple 
decrease of excitability to coil and cells, changes which 
are usually spoken of as quantitative changes. 

2. Changes in the nature or quality of the reactions or 
qualitative changes. These are the reactions of de- 
generation both complete and partial. 

3. The condition of total loss of all visible contrac- 
tions both to coil and to cells must also be consid- 
ered. It has a very definite significance, but its 
interpretation is not always the same, though it is 
always a grave sign. (See also § 140). 

135. Quantitative changes. — {a). Increased or de- 


creased irritability to coil currents. — Before forming a dia- 
gnosis of increase or decrease of excitability it is neces- 
sary to keep in mind the importance of measuring the 
resistance of the patient at the same time, because 
without the galvanometer it is not easy to known how 
much of the result depends upon altered resistance and 
how much on altered excitability. 

In unilateral disease increased or decreased excita- 
bility is shown by differences in the behaviour of the 
two sides. If the normal side be first tested an increase 
of excitability will be shown on the affected side if the 
minimal contraction shows itself with a lesser current. 
If both sides are affected, then an increased excitability 
is inferred if the minimal stimulus is seen with currents 
which are weaker than those which the operator has 
taught himself to recognise as usual in healthy people. 

{b). Increased or decreased excitability to battery current. — 
Simple increase of excitability is shown by the develop- 
ment of KCC with a smaller galvanometer deflection 
than usual, by the ready production of duration tetanus, 
and generally by the easier production of all the con. 

Simple diminution of excitability is shown by in- 
creased difficulty in the production of all the contrac- 
tions. A stage may be reached when they can be 
obtained only with strong currents, and finally all 
reaction may disappear ; excitability is then said to be 
lost or abolished. 

Increased excitability of the nerves and muscles is 
not very common, when it does occur it represents 
phases of irritation, and therefore it may be seen in the 
early stages of several disorders (such as tabes, chronic 
myelitis, hemiplegia) where at a later period the re- 
actions become diminished. 


Simple diminished excitability occurs in many old- 
standing nervous diseases, in myopathic muscular 
atrophies, in some cases of peripheral neuritis, and 
generally in wasted muscles. 

The recognition of increased or decreased irritability 
is easy when the increase or decrease is considerable, but 
to diagnose slight increase or slight decrease demands 
the greatest care, as there are miany disturbing factors 
to be guarded against. With the battery current a 
careful attention to galvanometer readings is the best 
guide, but even then one has to consider the differences 
which may depend upon the place of the testing elec- 
trode, for a slight movement away from the motor point 
will make the current less effective, and so simulate a 
decrease of irritability and again unequal pressure of 
the electrode on the two sides may cause an apparent 
difference in irritability, for with increased pressure the 
electrode is pushed nearer to the nerve or muscle owing 
to the elastic yielding of the subcutaneous tissue. 
Again the resistance of the skin may vary greatly 
during a test, and it usually falls while the testing is 
in progress, and this complicates matters. With induc- 
tion coil testing there is no galvanometric means of 
checking off the strength of the currents employed, and 
one has to fall back upon estimations of the voltage 
given by the coil. This leaves an opening for errors 
due to differences in resistance. Sometimes the skin 
resistance in a paralysed limb may be greatly increased, 
through alterations in the texture of the skin which 
covers it. Consequently when there is a question of 
carefully determining small decreases or increases of 
irritability, measurements of the resistance must first be 
taken as carefully as possible, and the situation of the 
electrode upon the skin must be carefully marked. 



The diagnostic value of small quantitative changes is 
not very great, so happily their determination is not of 
the first importance. 

The electrical properties of the testing circuit have 
also a decided influence upon the apparent excitability 
of nerve and muscle, and this introduces fresh dis- 
turbing factors when the results of testing with one 
apparatus are compared with those of a different one. 
Dr. Dubois in a very instructive paper'*"^ on the physio- 
logical effects of the continuous current has clearly 
shown that the presence of resistances in the testing 
circuit lowers the stimulating effect of a current of 
given magnitude, thus a current of three milliamperes 
passing through a circuit composed of the body and of 
a resistance is less effective in causing a muscular con- 
traction than a current of three milliamperes traversing 
the body in a circuit without any other external resist- 
ance, and he further goes on to prove that any increase 
in the self-induction of a testing circuit acts in the same 
way and lowers the stimulating effect of the current by 
retarding the rate of growth of the current at the 
moment of closure, which is the moment also of testing. 

A stimulus is effective in proportion to the suddenness 
with which the current rises to its maximum, and the 
greater the self induction of the circuit the slower this 
rise becomes. The presence in the circuit of a milli- 
ampere meter, which is an instrument of high self- 
induction, will therefore tend to increase the magnitude 
of the current required to cause contraction in the 
muscles and this will be more marked with delicate 
galvanometers wound with many turns of wire than it 
will be with smaller instruments. By shunting the 
galvanometer (§ 86) or better still by the use of a 
* Arch, (ft'lectricite medicale, i8g8, page i. 


condenser of large capacity (one microfarad) (§ 33) 
connected in shunt to the galvanometer terminals, the 
testing current may be made more effective and the 
minimal contractions obtained with smaller currents. 
The self-induction of resistances interposed in the 
circuit will equally influence the results of testing 
with coil currents. 

136. Qualitative changes — The reaction of de- 
generation. — This term was introduced to signify the 
altered electrical reactions which occur in the nerves 
and muscles under certain definite morbid conditions, 
the peculiar feature being that the change is not only 
a quantitative one, but also a qualitative one ; that is to 
say, there is an alteration in the quality of the response 
which the degenerate muscles make to the battery cur- 
rent. KCC often becomes- relatively less easily elicited 
than ACC, though this is not invariably the case, and 
the contraction provoked is a slow and sluggish one, 
differing greatly from the very rapid contraction given 
by a normal healthy muscle. 

This reaction of degeneration (usually symbolised by 
the abbreviation RD) is of very great importance. Its 
discovery and development arose from an observation 
of Baierlacher in 1859, that the muscles in a case of 
facial paralysis did not respond to the coil, but reacted 
with unusual force to the battery current, and to Erb's 
careful study of the symptom then first made known, 
we owe the most important fact connected with elec- 
tricity in medical diagnosis. 

The investigation of the reaction of degeneration has 
been pursued both clinically and experimentally, and 
its value consists in the fact that when it is present we 
can diagnose a break in the nervous link which con- 
nects the end plate of the muscle with its "nucleus of 



origin " in the grey matter of the anterior cornu of the 
spinal cord ; the lesion therefore must either be in the 
grey matter of the anterior horn in the cells from which 
the nerve fibre starts, or in the course of the nerve fibre 
from there to the muscle. The reaction of degeneration 
does not follovi^ central nerve lesions which are wholly 
above the spinal ganglion cell whence the nerve fibre 
springs, nor does it follow affections which are confined 
to the muscle fibres proper (idiopathic muscular 

In RD the irritability of the nerve disappears en- 
tirely, and therefore stimulation of it has no effect, the 
muscle on the other hand retains its irritability to the 
battery but not to the coil current, that is to say its 
irritability is still present for certain stimuli. It does 
not react to the interrupted current of an induction coil, 
but it reacts to a mechanical shock and to a battery 
current slowly made and interrupted. If the battery 
current be made and broken rapidly by an automatic 
vibrator, the muscle will not respond to it, or it may 
respond once at the first closing of the circuit. A 
curarised muscle will still react to coil currents, though 
not so readily as a normal muscle, therefore the total 
loss of " faradic " irritability in a muscle showing the 
reaction of degeneration signifies something more than 
a torpor of the intramuscular nerve endings, it means 
that a trophic change has occurred in the muscle pro- 
toplasm, and further evidence of the change is seen in 
the frequent production of ACC more easily than KCC. 
This alteration of the relative effect of the poles, is not 
an important part of the reaction of degeneration, for it 
is not constantly present. Another important alteration 
is that the irritability of the muscle to the battery cur- 
rent may be greater than in health, strong contractions 


being set up in the affected muscles by currents which 
are too weak to produce any visible movement in neigh- 
bouring healthy muscles. 

It is only in fairly recent cases that the phase of 
exaltation of muscular irritability is manifested, and in 
most cases of RD, that is, of course, if recovery does 
not set in, the later stages show a progressive loss of 
irritability of the muscle. 

Erb's definition of the reaction of degeneration is the 
following : — " It is characterised by the diminution and 
loss of faradic excitability in both nerves and muscles, 
whilst the galvanic excitability of the latter remains 
unimpaired, is sometimes notably increased and always 
undergoes definite qualitative modifications." 

137. The course of the reaction of degeneration. 
— At first for two or three days after the onset of the 
lesion there will be in the nerve a progressive lowering 
of all electrical excitability, and after this the irrita- 
bility of the nerve will be completely abolished and will 
remain so unless recovery takes place ; in that case the 
return of motor power may precede the return of elec- 
trical irritability. 

In the muscle the reaction to coil currents runs the 
same course as in the nerve. To battery currents, on 
the other hand, there is at first a progressive lowering 
of excitability, but by the end of a week this is replaced 
by an increase of excitability to a point much above the 
normal, with sluggishness of contraction and sometimes 
with ACC > KCC ; after a period of three, six, or eight 
weeks, diminution of excitability sets in, and the 
diminution is progressive until at last it may disap- 
pear entirely. 

In cases which recover it often happens that the 
power of voluntary movement will return some little 

R 2 


time before the response to electrical stimuli, but in 
other cases both may return simultaneously. 

When a nerve has been completely divided the 
changes which occur are as follows : — 

1. A sudden loss of voluntary power in the muscles 
supplied by the divided nerve. 

2. Arrested conductivity of the nerve — therefore abo- 
lition of excitability in the muscles supplied from below 
the wound, when both electrodes are placed on or near 
the nerve trunk below the seat of injury. 

3. For two or three days, sometimes only for forty- 
eight hours, some trace of contractility to coil currents 
remains present in the muscles when the electrodes 
are applied on the distal side of the section or on the 
bodies of the muscles. The disappearance of this re- 
action shows degeneration and loss of irritability ex- 
tending down the intra-muscular nerve fibres to the end 

4. Increased "galvanic" irritability accompanied by 
a relative increase of anodal excitability. The anodal 
closing contraction (ACC) often approaching in ampli- 
tude and ultimately exceeding (about the sixth or 
seventh day) the cathodal closing contraction (KCC). 
The electrodes are applied, one on an indifferent part of 
the body, and the other on the muscle, and the direc- 
tion of the current is alternated on purpose to compare 
the amplitude of the contractions produced. The cur- 
rent is conveyed, not by the nerve, the continuity of 
which is severed, but by all the tissues intervening 
between the two electrodes. 

5. As the muscle degenerates its irritability steadily 
declines. The final disappearance of all irritability 
may not take place for many weeks, or months, or 


6. If union of the divided nerve takes place, volun- 
tary movement in the muscles again becomes possible ; 
muscular regeneration commences ; the electrical reac- 
tions gradually return and the irritability again very 
gradually rises to its former condition. 

Such is a review of the typical electrical reactions of 
nerve and muscle after complete severance of a nerve, 
and these reactions modified in various ways, by the 
amount of destruction to the motor centres or cells, or 
the conducting nerve fibres, are characteristic of the 
several nervous diseases where qualitative changes in 
the electrical reactions are to be observed. 

Professor Erb is careful to remind his readers that 
various deviations from the typical form of the reaction 
of degeneration may be met with. He says: "You 
must not expect to find in every pathological condition 
so great a uniformity in the course of these modifica- 
tions as is to be met with in experiment, or in a simple 
traumatic lesion of the nerves ; this does not often occur 
in disease, where many deviations may be caused by 
the nature of the injury, different affections of trophic 
influences, occasional improvement, or new elements of 
disturbance following one upon another ; and one is not 
warranted in concluding from some irregularity, such as 
presents itself in long-standing cases, that one has dis- 
covered some fresh anomaly. The time at which repair 
takes place determines great differences in the general 
manifestation of the reaction of degeneration. If this 
happens early the nerve may be endowed with galvanic 
and faradic excitability while the changes of the muscle 
are at their height, these latter cannot be reformed so 
quickly, and require for the purpose some lapse of time. 
It may happen then, that when the nerve is excited the 
muscle responds with normal contractions, but still 


when stimulated directly exhibits the reaction of de- 
generation. But if repair sets in very late, it may be 
that the muscular excitability is already greatly dimin- 
ished when the excitability of the nerve begins to be 
slowly restored. There is, therefore, an indefinite 
number of special cases, which nevertheless may be 
mastered by carefully attending to the conditions of 
time and other circumstances." 

138. Partial reaction of degeneration. — This 
term is applied to cases in which some degree of 
contractility for coil currents is present although there 
is decided sluggishness of contraction of the muscle for 
the battery current. 

Muscles having the partial reaction of degeneration 
may exist in a limb side by side with others showmg 
the complete form, and other muscles may show other 
degrees of transition between the normal state and par- 
tial or complete degeneration, but the existence of such 
a condition as that in which the muscles show a reaction 
of degeneration, though connected to the central nervous 
system by a nerve still functional, or at least capable of 
conducting impulses to the muscle, makes it more than 
ever difficult to understand the exact meaning of the 
muscular changes which give rise to the phenomena of 
the reaction of degeneration. Erb especially insists 
that this partial form of RD may occur in cases of 
commencing recovery from complete reaction of degen- 
eration, or it may be present at the commencement of 
an attack, and may be followed at a later period by 
the complete form in the same nervous and muscular 

The existence of "partial RD " makes it important 
in testing always to confirm the results of the coil test 
by the application of the battery current test. If partial 


RD be present there is usually a perceptible alteration 
in the coil reactions, but this may be overlooked, and in 
that case conclusions drawn from the presence of coil 
reactions alone would seriously mislead. 

139. Conditions which lead to the reaction of 
degeneration. — Briefly speaking RD follows damage 
in that region of the motor path to which Dr. Gowers 
has given the name of the " lower segment," that is to 
say, that part of the course of a motor fibre which com- 
mences at the motor ganglion cell of the nucleus of 
origin or of the anterior cornu, and is continued down 
as a nerve fibre to the motor end-plate beneath the 
sarcolemma of its muscle. It does not follow damage 
limited to the " upper segment," and in the lower seg- 
ment a certain degree of severity in the damage is 
necessary to produce it. RD is found after division, 
destruction, or injury of motor nerve trunks, and after 
disease or injury affecting the ganglion cells of the 
anterior cornu cf the cord, or the corresponding nuclei 
of origin in the case of the cranial nerves. Under one 
or other of these morbid states can be grouped pressure 
palsies of all kinds, division or laceration of nerves, 
difl'erent forms of peripheral neuritis, poliomyelitis an- 
terior both acute and chronic, muscular atrophies from 
disease in the spinal cord or in the nerves (but not 
atrophies of muscular origin), also acute and chronic 
myelitis, lead poisoning and diphtheritic paralysis. The 
reaction of degeneration is not found in the paralysis of 
cerebral disease (except when the implication of the 
nuclei of origin or of the nerve trunks of the cranial 
motor nerves produces a reaction of degeneration in the 
muscles which they supply) nor does it occur in diseases 
limited to the white matter of the cord, nor in hysterical 


The following history shows the value of the recog- 
nition of RD in a doubtful case. A woman fell down 
some stone steps and cut her head. She was picked 
up insensible and paralysed in one arm, and in this 
state was brought to the hospital. It was uncertain 
whether her paralysis was due to the head injury or 
not, and different people took different view^s of the 
case, but electrical testing showed RD in many muscles 
of the paralysed arm, thus proving that the paralysis 
was not due to the blow on the head, but to an injury 
to the brachial plexus caused by the fall. The question 
of an operation to explore the wound of the head could 
therefore be dismissed. 

140. Prognosis in the reaction of degeneration. 
— " Other things " — that is the cause and nature of the 
disease — "being the same, the lesion is serious, the 
probable duration of the disease longer, the definite 
prospect of a cure more remote in proportion as the 
reaction of degeneration is developed and complete, 
and in proportion to the stage which it has reached " 

He instances the value of the symptom in the prog- 
nosis of simple facial palsy, distinguishing three forms, 
(i) Mild^ electrical reactions normal, prognosis favour- 
able, probable duration three weeks. (2) Intermediate, 
partial RD, duration one or two months. (3) Serious, 
complete RD, prognosis bad, duration three, six, nine 
months or longer. 

At the same time he emphasizes the importance of 
the saving clause with which the quotation opens, in- 
sisting that it is not permitted to reason alike in all 
paralyses, without giving due weight to the importance 
of the lesion producing them, for instance the prospects 
of a case of facial palsy from caries of the petrous por- 


tion of the temporal bone cannot be expected to re- 
semble those where the mischief has been set up by a 
mere exposure to cold ; and electrical reactions which 
are a guide to prognosis in cases of the latter type must 
not be forced into a similar interpretation for the 
former. There is an important remark of Dr. de 
Watteville's which may be quoted : — " It may not be 
unnecessary to guard the student against the error of 
looking upon the occurrence of alterations in the re- 
sponse of nerves and muscles as in itself indicative of 
irreparable mischief. On the contrary, RD is often of 
far more favourable prognosis than normal reactions, 
which we have already found to be consistent with 
absolutely incurable lesions, involving complete para- 
lysis. Intractable spasms, tremors, or convulsions again 
are never accompanied by any notable disturbance, 
quantitative nor qualitative, of the electrical re- 

To this may be added that the electrical test can 
only be used to obtain information as to a certain por- 
tion of the nervous system, namely, the lower segment, 
and also of the muscle at the time of making the test, 
and if inferences are to be drawn from the observations 
made it will be necessary for the observer to take many 
other circumstances into consideration, and it will rest 
with the observer to draw the correct inferences from 
his facts. 

Among the practical points which continually arise in 
connection with the RD, perhaps none are more impor- 
tant than the giving of an answer to the question 
whether a nerve trunk is divided or only hurt. The 
question is one of the utmost importance, because the 
whole future conduct of the case rests upon the answer 
and it may be difficult to answer it because RD will 


equally follow division and severe injury. Perhaps it 
will be useful to consider an actual case : — A barber on 
board ship was at work with a pair of scissors when 
the vessel gave a heavy roll and the patient accident- 
ally plunged the scissors into his arm-pit. It bled a 
good deal and was bandaged up tightly and remained 
so for several days until the ship came into port. He 
was then found to have an extensive paralysis of the 
forearm and traumatic aneurysm of the axilla. I was 
asked to report on the paralysis and to state whether 
any nerves were divided or not. He showed RD in 
the ulnar and musculo-spiral areas. In the latter area 
one muscle, the triceps, did not show complete RD, for 
it retained its contractility to the coil in part, while in 
the ulnar area the paralysis was not absolute, the wast- 
ing was not extreme and sensation though impaired 
was not altogether lost. On these grounds the report 
was given that the musculo-spiral nerve was not 
severed, and that in all probability the ulnar had also 
escaped. His nerve trunks accordingly were not ex- 
plored, and under treatment by electricity he made a 
gradual but complete recovery. His paralysis probably 
had been caused by the tight bandaging and not by the 
punctured wound. 

Another case was one of gunshot wound of the lower 
half of the arm with extensor paralysis. He was exam- 
ined electrically about five weeks after the accident, 
when healing of the extensive lacerated wound had 
made good progress. There was RD of all the ex- 
tensors, but wasting was not extreme, the contractions 
were of very good volume and the sluggishness was not 
conspicuous. Judging that if the nerve had been com- 
pletely severed the reaction of degeneration would have 
begun to enter the stage of decreased irritability, and 


finding it to be not decreased an opinion was given that 
the trunk of the musculo-spiral had escaped. The later 
history of the case proved this opinion to have been 

Thus the diagnosis between severance of a nerve and 
serious injury without severance cannot be made with 
certainty by electrical testing, although a careful scru- 
tiny of all the phenomena, motor, sensory, vasomotor 
and trophic will usually enable one to form a correct 

Anything incomplete in the symptoms of paralysis, 
of anaesthesia and of wasting points to a non-severed 
nerve, and the progress of the symptoms in a case 
watched for a time will also throw light upon the 
question. The reactions will rapidly become degraded 
in total division, and all the symptoms will become 
worse, while in cases of injury without division the 
patient may show slight improvement from week to 

Another common problem in practical testing is the 
following : — A nerve-trunk has been operated on and 
sutured ; after the lapse of a certain period of time the 
case is sent for a report as to whether the sutured ends 
have become united, the patient being anxious owing to 
there being no return of voluntary power. Here, again, 
the mere testing of the muscles does not help much. 
Even in favourable cases the reaction of degeneration 
may show a general degradation in character even 
when sensation and voluntary power are returning 
steadily; indeed it is common to find loss of all 
reactions or the merest remnants of the RD in cases 
more than half recovered. One cannot expect normal 
reactions until late in the course of the case, and usually 
they return too late to be of much prognostic value. If 


contractility to the coil returns early it is a good sign 
and foreshadows rapid recovery. 

After operations for suture of divided nerves the chief 
need on the part of patient and surgeon is patience. 
Divided nerves are slow in recovery, especially if an 
interval has passed between division and re-union ; 
reactions of normal quality are slow to re-appear, 
particularly when there is a long stretch of nerve be- 
tween the wound and the muscle tested ; the most 
distal muscles suffer the most, and regain power and 
reactions the latest. Even in a simple case of division 
of a nerve in a clean wound, and suture the same day, 
an interval of one hundred days may elapse before there 
is any return of power. 

141. Recent study of electrical reactions. — In 
the Bulletin Officiel de la SocieU d' El ectr other apie, 1897, will 
be found two valuable papers on this subject the one by 
Doumer, the other by Huet. The former takes the line 
that the reaction of degeneration is best viewed as a 
combination of several alterations from the normal, each 
probably having its own special meaning, and he then 
proceeds to an analysis of the various conditions of the 
reaction in disease with the object of determining what 
may justly be inferred from each. He insists upon the 
difference between a nervous impulse and an electrical 
one, pointing out that an electrical impulse reaching a 
motor nerve fibre is first translated into a nervous 
impulse and then passes on in that form along the 
nerve and to the muscle. Further he argues that the 
nerve may fail either to effect the translation or to 
convey the translated impulse, or that the muscle 
receiving a proper impulse may fail to respond to it 
by a proper contraction. 

Those who are familiar with electrical testing are well 


aware of the fact that notable variations in degree are 
to be seen in the reaction of degeneration. Some of 
these are certainly due 'to a general degradation of the 
state of the muscle in cases of long standing, which 
makes the contractions more difficult to see, and de- 
prives them of some of the sharpness of character which 
one might expect. Examples of this kind in which the 
RD can still be observed but which are not good 
cases for the demonstration of typical RD are common 
enough. The polar change with predominance of ACC 
over KCC is referred to by Professor Erb as one of the 
most constant phenomena in medicine, but in my ex- 
perience and in that of others its appearance is so 
inconstant as to be absolutely without diagnostic value 
as a part of the reaction of degeneration. Again, the 
degree of sluggishness, or in other words the duration of 
the contraction produced in muscles by the closure of 
the current from the cells varies within wide limits ; so 
that at times one may see a contraction so long and 
slow as to resemble a veritable peristalsis of unstriped 
muscle, while in other cases it is only after minute and 
oft repeated comparisons with sound muscles that one 
can at last determine whether the contraction to cells 
is or is not altered. 

It is probable that the relative order of appearance of 
ACC and KCC may depend upon chance positions of 
the testing electrode. See § 116 last part and fig. 65 
for the virtual polarity of parts around an electrode. 
Thus a positive electrode near to a motor point but not 
exactly over it might set up a virtual negative polarity 
at the motor point and vice versa. 

142. Duration tetanus. — Closely associated with 
the reaction of degeneration one may notice a ready 
production of Duration Tetanus, that is to say the 


persistence of a notable degree of contraction to the 
battery current so long as the circuit remains closed 
(§ 117). A small degree of contraction remainder is 
usual in all muscles during the time which lies between 
the closing and opening of the circuit of the cells, but 
ordinarily it is not perceptible to the eye with the 
currents commonly used in testing. If it becomes 
conspicuous it may signify a morbid change like that 
of RD ; with which it is often though not always 
associated. The Myotonic reaction is something anal- 
ogous and occurs in a rare condition called Thomsen's 

143. Study of muscle contractions by the 
graphic method. — The graphic method of record- 
ing tracings of muscular contractions deserves more 
attention. A certain amount of work has already 
been done in this way and an apparatus has been 
described by Radiguet with which the tracings may 
readily be taken. It is made by Chardin (7 Rue 
Linne, Paris) and consists of a combination of key 
electrode (§79) with a tambour for receiving the impulse 
and transmitting it to a revolving drum. What is 
wanted most is a long series of observations upon 
muscle contraction with tracings taken under varying 
conditions and combined with careful time tracings in 
order to collect facts upon which to found an analysis of 
the conditions under which variations occur. The 
latent period, the phase of contraction, and the phase 
of relaxation all need to be studied. So too the form of 
the electrical impulse requires study in conjunction with 
such tracings. The points referred to in § 135 make it 
probable that something might be learnt from a com- 
parison of the effect upon contraction of circuits having 
self induction with that of circuits having condensers 
inserted in them to neutrahse their self-induction. 


Mendelssohn has applied the graphic method to the 
study of muscle curves, and has described modifications 
under the names of " curve of spastic muscle," "para- 
lytic curve," " atrophic curve " and " degenerative curve." 
These though interesting are not yet sufficiently deve- 
loped to have much diagnostic value. The " longi- 
tudinal reaction" described by Doumer in 1891 is the 
production of a sluggish contraction by anodal or 
cathodal closure (cells), the electrodes being so ar- 
ranged as to allow the current to traverse the whole 
length of the muscle, the motor point not being con- 

It has been said that a sluggish contraction in a 
muscle is occasionally set up when the electrode is 
applied to a remote point of its nerve trunk ; this con- 
trasts with the loss of response of the nerve trunk which 
usually is associated with sluggish contraction in a 
muscle. It has also been said that the induction coil 
current applied to a motor point may set up a sluggish 
contraction instead of a tetanus. These are curiosities 
or errors of observation. 

144. Sensory nerves. — There is but Httle to be said 
on the subject of alterations in the electrical reactions 
of sensory nerves. Simple increase of sensibility and 
simple decrease of sensibility can be detected, and ap- 
parently the degree of electrical sensibility corresponds 
rather with the degree of perception of pain than with 
that of perception of tactile sensations. This has been 
determined in diseases in which these two forms of sen- 
sibility are often affected in unequal degrees. 

For investigating the electro-cutaneous sensibility the 
interrupted current must be employed, and it is as 
important to notice and take into consideration the 
amount of skin resistance, as it was in examining the 



muscles, and in the absence of a suitable galvanometer, 
the sledge coil must be used, and the distance of secon- 
dary coil from primary must be noted and recorded. 
For testing the sensibility of the cutaneous nerves one 
may use a metallic brush for the active electrode and 
should not moisten the surface of the skin ; or an elec- 
trode devised by Erb may be used. It consists (fig. 68) 
of a bundle of 400 metallic wires sheathed and var- 

FiG. 68. — Cutaneous testing electrode, a. Side view. b. End view. 

nished, enclosed in a vulcanite case of about two centi- 
metres in diameter. At one end the wires are all put 
in metallic communication, and are attached to an or- 
dinary electrode handle, the other end is polished, so 
that when applied to the skin it has the effect of a 
smooth surface. It covers an area of skin of about two 
centimetres in diameter, and into this the current enters 
in 400 parts. Thus a more regular action on the nume- 


rous nerve terminations is secured, and with the inter- 
rupted current the degree of stimulus may be estimated 
for the first appearance of sensation, and for the first 
perception of pain. The following remarks" on the 
subject of estimating anaesthesia, are of great value in 
showing how easy it is to be misled in testing a patient 
for anaesthesia. " The patient should always be placed 
in such a position that it is impossible for him to see 
the hand of the surgeon, or the area which is under 
observation. He should not be allowed to move the 
finger or other part touched, for thereby the muscular 
sense comes to the aid, and falsifies observations. The 
impact of the instrument used should be very light, for 
a patient can frequently discern friction on an anaes- 
thetic surface by means of vibrations carried by the 

tissues to surrounding healthy nerves I have often 

seen the sensory power of a presumably anaesthetic part 
tested by rubbing the part with the finger while the 
patient's eyes were averted, and almost always with the 
result that the stimulus was correctly perceived, and 
that a returning sense of touch was diagnosed by the 
investigator. Such a conclusion is entirely erroneous, 
for as Letievant has pointed out, any person can per- 
ceive friction applied even to the finger of another 
person, if it be held between the bases of two of his 
own fingers, i.e., the vibrations are conveyed to and ap- 
preciated by the nerves of the surrounding digits. How 
much more must this be so in the case of a divided 
median nerve when healthy nerves are present on part 
of the very finger to which the friction is applied. 
Friction should, therefore, never be used as a test of 
sensation, for the same reason the part which is being 

* " Lectures on Injuries of Nerves," Lancet, June, 1887. A. A. 



examined should never be pushed or thrust away from 
the position in which it Hes." 

St. John Brooks has drawn attention to the fact that 
in the hand the areas supphed by the different sensory 
nerves overlap considerably. 

An ingenious method of testing the sensibility of a 
patient is to use one's own finger-tips as the electrode, 
for by proceeding in this way the operator has his own 
sensations as a guide, and can use them to check the 
patient's statements. If an opening and closing key, 
out of the patient's view, be included in the circuit the 
current can be turned off and on and the patient told 
to say when he feels this being done. A systematic 
examination of the different parts of the body by this 
method will show how greatly the sensibility varies in 
different regions. To do this one electrode is applied 
to the patient, and one to the operator, the circuit will 
then be closed when the operator places his finger on 
the patient. The operator then feels the current which 
is passing to the patient, and can judge from his own 
sensations of the degree of sensibility possessed by the 

145. Nerves of special senses. — The auditory nerve. 
— Of the nerves of special sense there is one which we 
may discuss at present, namely the auditory, because of 
the electrical treatment of tinnitus aurium. We have 
already pointed out that in health it is possible to 
obtain reactions when a battery current passes through 
the auditory nerve, and that like the motor nerves, the 
auditory responds more readily to kathodal than to 
anodal stimulation, and generally exhibits the same 
electrical reactions, the response being the production 
of a subjective sensation of sound ; but in certain cases 
the auditory nerve answers to electrical currents more 
readily than it does in health. In these cases it is 


supposed that there is a state of hyperaesthesia or of 
irritation in the nerve, and that the tinnitus is really 
the expression of that irritable state. In the simplest 
form of hyperaesthesia the kathodal closure gives sounds 
which persist so long as the current is flowing but cease 
with the opening of the circuit, while the anode (anodal 
closure) diminishes or abolishes the sound, which does 
not return during the passage of the current, and often 
not for hours after the current has been stopped, pro- 
vided that the stoppage be gradual. So too in cases of 
severe deafness the reactions of the auditory nerve may 
be tested to determine its condition. 

Fig. 69. — Aural electrode. 

The auditory nerve can best be tested or stimulated 
by a bifurcated or divided electrode, which can be 
applied to both ears at once. At a pinch a binaural 
stethoscope answers very well, small pads of moistened 
cotton being substituted for the ivory ear pieces ; these 
ends may be introduced into the meatus, or, better, 
may be applied just in front of the tragus and kept in 
place without unnecessary force by an elastic band or 
spring.''' If a stethoscope is used, the lower portion can 

* Messrs. Arnold and Son have made a very convenient divided 
electrode for this purpose by converting the framework of a light 
binaural stethoscope. 

S 2 


be removed, and the tubes closed up by small corks, the 
wire from the battery is clamped to the metal, and the 
other electrode may be applied to the sternum or back. 
When only one ear is to be influenced only one of the 
sides of the binaural electrode is moistened. 

Hyperaesthesia of the auditory nerve is frequently met 
with in ear disease, but it is not present in all cases of 
tinnitus ; when tinnitus and electric hyperaesthesia co- 
exist the subjective noises are readily influenced and 
controlled by galvanism, and many cases of cure have 
been effected. If the tinnitus does not respond to the 
electrical test it is less likely to be benefited by treat- 
ment. The opposite condition to electrical hyperaes- 
thesia, namely, electrical torpor of the auditory nerve, is 
also known. 



General Therapeutics. 

Effects of electricity. Choice of current. Strength of current. 
Choice of pole. Methods. " General faradisation." "Galvano- 
faradisation." Galvanisation of the cervical sympathetic. Cen- 
tral galvanisation. Self treatment by patients. 

146. Eifects of electrical treatment. — The elec- 
trostatic methods of treatment have been already con- 
sidered in Chapter VI. We have now to consider the 
methods of procedure with the battery and induction 
coil currents and with the sinusoidal currents produced 
by the alternate current dynamo. In either case the 
treatment may be general or local. Of general methods 
the one most fully deserving the name is treatment by 
the electric bath, which will be fully dealt with in the 
next chapter. 

In commencing the study of electro-therapeutics the 
first questions to arise are the following: — (i) What 
results are to be expected from electrical applications ? 
(2) When should the constant current be used, and 
when the interrupted ? (3) What is the proper strength 
of current and the proper duration of treatment ? (4) 
What is to be the direction of the current and which 
pole is to be applied to the affected part ? (5) What 
are the manipulations required ? 

The effects produced by electrical treatment may be 
arranged thus : — 

(a) Stimulating and trophic effects. — Electricity acts as a 


stimulus, not only to the contractile tissues, both directly 
and through their motor nerves, but also upon the sen- 
sory nerves, and through them upon the central nervous 
system. It also influences the vaso-motor system. The 
vaso-motor influences play an important part in the 
relief of the pain and congestion which occur in so 
many morbid states, as will be seen when the treatment 
of sciatica and of joint aflections is under consideration. 
In any ordinary electrical application the vasomotor 
eff"ects upon the vessels of the skin are readily perceived, 
particularly when the battery current is used. 

All living tissues are stimulated to greater activity by 
electrical currents, particularly when the currents are 
variable. D'Arsonval has shown that under the action 
of a varying current the elimination of urea and carbon 
dioxide is remarkably increased, even if there be no 
muscular contraction set up, so that the effect is not 
merely secondary to any muscular contractions produced 
by the treatment, he also found a similar increase, 
though to lesser degrees with electrostatic charging, 
but with constant currents of unvarying flow the efl"ect 
upon the respiratory exchanges was very slight. 

The improvement in health shown by rickety children, 
and by anaemic and debilitated persons when they are 
treated by general electrification with alternating or 
interrupted currents is conspicuous ; they increase in 
weight, they become rosy cheeked, and they eat and 
sleep better. Other observers have shown that currents 
passed along the spine can augment the muscular force 
of the person so treated. 

These effects are to a certain extent shared by other 
modes of stimulation, as for instance, by massage, by 
treatment with hot and cold douches, followed by fric- 
tion with rough towels, and so forth ; but electricity has 


certain advantages over these other modes of stimula- 
tion, from its greater power of setting up active mus- 
cular contractions, and from the ease v^ith which it can 
be directed to any required parts, and regulated as to 

The effects which peripheral stimulation exerts upon 
the central organs play an important part in electrical 
treatment, and afford an explanation of the benefits 
which follow even in cases where the treatment has 
been applied to the peripheral parts only. 

(b) Electvotonic effects. — These have been already con- 
sidered in § 115, and the physiological effects there 
described have been made the basis of a method of 
treatment by the continuous current. With the alter- 
nating currents of the induction coil electrotonic states 
cannot be expected, but with constant currents the 
phenomena of electrotonus may be kept in mind in 
treatment, for they show when the exciting action of 
the exalted irritability of kathelectrotonus is to be 
brought to bear upon a part, as in paralysis ; and when 
the calming effects of the diminished irritability of 
anelectrotonus are more desirable, as for the relief of 
pain and spasm. 

(c) Electrolytic effects. — The changes produced by elec- 
trolysis are most manifest at the surfaces in contact 
with the electrodes. In general medical treatment 
these electrolytic effects are undesirable, as they tend 
to produce injurious chemical action upon the skin, and 
are therefore guarded against by interposing some moist 
material between the metal of the electrodes and the 
surface of the body. In surgery the destruction of 
tissue by means of electrolysis is used for the cure of 
naevi and other superficial growths, for the removal of 
superfluous hairs, and for strictures, and it will be dealt 


with in a separate chapter. Usually needles attached 
to the poles of the battery are thrust into the substance 
of the part to be destroyed. In addition to the electro- 
lytic action at the region of the poles, there is also an 
interpolar action, through which molecular interchanges 
take place in the tissues along the whole line between 
the poles, the exact effects of these interpolar changes 
cannot be clearly defined, but it may justly be con- 
sidered as producing some action ; and perhaps some 
of the trophic or " alterative" effects which follow elec- 
trical treatment are due to these molecular movements 
and exchanges. 

(d) Osmotic effects. — These have been considered in the 
chapter on physiology (§ 125) which see. 

147. Choice of method. — A very large part of the 
benefits derived from electrical applications can be 
ranged under the heading of stimulation, and generally 
speaking it may be said that for stimulation pure and 
simple the induction coil is the best ; certainly it is to 
be preferred in paralysis of muscles if they are able to 
react to it, but if they present the reaction of degenera- 
tion then the constant current may have some advan- 
tages. Fashion has had much to do with determining 
the choice between the two modes of treatment. 

Duchenne was a firm believer in the superiority of 
the coil treatment for all kinds of paralytic conditions, 
and Remak was as warm a supporter of the constant 
current. The former writer declared that he had met 
with far better results from the interrupted than from 
the constant current. The latter was as confident of 
the superiority of his method. 

Whatever benefits may be produced by electrolytic 
or electrotonic effects must be possessed by the battery 
alone ; stimulation, direct and reflex, vasomotor and 


trophic effects can be produced by the induction coil, and 
as these effects form so large a part of what is desired 
in cases coming for electrical treatment, the induction 
coil is the instrument for use in the majority of cases. 

The battery has been preferred to the coil for the 
treatment of muscles which show the reaction of de- 
generation. The reason given for this is that the 
battery current will make such muscles contract when 
the induction coil can no longer do so. If the visible 
contraction of the muscle were the measure of the good 
done to it by the treatment, the reason would be a valid 
one. I have treated large numbers of cases showing 
RD with the interrupted current, and have obtained 
very good results in that way, and I consider that it is 
at least as useful as the battery current for all kinds of 
paralysis. When the battery current is used, and the 
electrode is moved over the surface of any part, the 
effect is that of a very gradually varying strength of 
current ~ applied in succession to the different parts 
touched by the electrode, and it differs from the in- 
duction coil current chiefly in the rate of variation. 

In order to determine whether the battery current is 
better than the induction coil for treating cases of 
paralysis, a long series of comparable cases must be 
treated by each method, and the results examined. I 
have been able to do this in the electrical department 
at St. Bartholomew's Hospital to a considerable extent, 
and I am satisfied that good results can be obtained 
with both methods. As it is probable that the effects 
of the two methods do not exactly coincide, it seems 
reasonable to advise treatment by both ; for example, 
to give a patient with muscles showing RD a treatment 
with the battery and with the induction coil, at each 


The sinusoidal current may be regarded as an im- 
provement on the induction coil current, and as useful 
in the same conditions. Its applications are best made 
in a bath of water, and will be considered in the next 

In conditions other than paralysis the battery current 
may be far superior to the coil. Coil currents may be 
too sharply stimulating, they may cause pain, they may 
not penetrate deeply enough, they may be unsuitable 
for influencing unstriped muscle, if vaso-motor effects 
are desired, or when the intestinal or bladder muscle is 
to be treated. For the relief of pain the battery current 
is the best. Some pains may be relieved by the induc- 
tion coil current applied as a counter irritant, but as 
a rule painful conditions and especially the pains of 
neuritis and neuralgia are unfavourably influenced by 
coil currents. With the battery current the degree of 
stimulation can be varied by varying the rate of change 
of current. A steady flow with the electrodes held still 
(stabile application) is the least stimulating to nerves 
and striped muscle ; if the active electrode is slowly 
moved over the part (labile application) stimulation is 
rather greater, and it is much greater with sudden 
makes and breaks of current, while finally the most 
profound stimulation is from reversals when the current 
is fully on. Considerations like these determine the 
choice of cells or coil, and in the different paragraphs 
which consider detailed diseases and their electrical 
treatment further precise indications will be found. 

148. Strength of current. — In determining the 
strengtn of current, it is necessary to remember that 
but little good is likely to follow torture, and that no 
needless pain should be inflicted upon the patient. 
With the coil the operator must gauge the strength 


of his current upon himself first, and must repeat the 
test with every increase in its strength ; a strict adhe- 
rence to this rule is the best plan by far of ensuring 
the proper amount of caution. Patients as a rule are 
extremely intolerant of painful shocks, and it must be 
remembered that the very name of electricity is enough 
to make many patients at least a little anxious or 
alarmed on their first trial of the remedy. It is there- 
fore wise always to exercise carefulness in the manage- 
ment of the instruments, in order not to appear to the 
patient to be reckless in handling them. 

With battery currents the galvanometer provides the 
means of regulating the dosage. For most forms of 
local treatment five milliamperes is sufficient, and may 
be too much for children or sensitive or nervous people 
at the commencement of a course of treatment ; and 
the current must not be switched on or off abruptly, 
but gradually, the patient being carefully watched for 
any signs of pain of discomfort. The current collector 
(§ 80) must be properly made and should be tested from 
time to time to see that it allows of alterations in the 
number of cells without any breaks of circuit ; when the 
applications are made to any part of the head or neck, 
additional care must be exercised, the effect upon the 
brain being very peculiar and unpleasant, especially at 
make and break. When large currents are required in 
the electrolysis of naevi or tumours, an anaesthetic must 
be used. In Apostoli's treatment no anaesthetic is used, 
although the current may exceed loo milliamperes. 
Toleration of so large a current is rendered possible 
by the use of a very large electrode for the cutaneous 
surface to reduce the density of the current per unit of 
area, and by the insensitiveness of the uterus to which 
the other pole is applied. 



Generally speaking, large currents are used when 
deep seated parts are to be treated, and the electrodes 
must be large in proportion to avoid pain and injury to 
the skin. 

The duration of each sitting may be on an average 
ten or fifteen minutes, but here again the patient's 
feelings must be taken into account, and the time 
shortened or lengthened as may seem advisible in each 
particular case. 

The number of sittings varies very much, usually a 
considerable number are required. It is best to tell the 
patient at the commencement that he must not expect 
a magical and sudden cure, but rather a gradual slow 
improvement. In some cases of infantile paralysis it 
may be necessary to continue treatment for several 
years. As a general rule it may be said that at least a 
month of treatment, with two or three sittings a week, 
is required to produce permanent benefit, but of course 
there are exceptions, and it is not possible to lay down 
any precise rules. It is usual for improvement to begin 
early if the treatment is likely to do good. In that case 
the patient will be encouraged to persevere. If at the 
end of a month of regular treatment there is no visible 
change, or if the improvement has ceased to be pro- 
gressive, then the treatment may be discontinued. 

149, The choice of pole. — With the alternate cur- 
rents of the secondary coil the influence of pole is 
reduced to a minimum, and the two electrodes may 
be considered to be of equal, or nearly equal value ; 
with continuous currents there are well marked differ- 
ences in the effects produced at the two poles. From 
electrolysis the region of the anode or positive pole 
becomes acid, and that of the negative alkaline in 
reaction, and there is a tendency to produce injury to 


the skin from the chemical products of the electrolysis, 
if the currents be large or if the electrodes are left long 
in one position. 

The sedative effect of the anode would seem to deter- 
mine its use in painful states, while the stimulating 
effect of the kathode and the greater ease with which it 
causes muscular contraction have determine the use of 
the negative pole in the treatment of paralysis. It is 
not possible to generalise further about the choice of 
pole, but instructions will be found in the chapters on 

The rule laid down by Remak for the direction of the 
flow of current was that the current should pass along 
the nerve fibres in the direction in which they conduct, 
namely, downwards to the periphery for treatment of 
motor affections, and upwards from the periphery for 
sensory affections. 

Brenner preferred to consider the direction of the 
current as of less importance than the influence of the 
poles ; and we should therefore speak of the choice of 
pole rather than the choice of the direction of the 
current, because the current does not run in straight 
lines from anode to kathode ; however, the distinction 
between direction of flow and choice of pole is after all 
a subtle one. To apply the kathode to the paralysed 
thumb muscles, the anode being at the nape of the neck, 
may reasonably be spoken of either as treatment by a 
descending current or as treatment by the negative pole. 
Those who object to speak of the influence of direction 
of current base their objections on the fact represented 
in fig. 65, that round a pole applied to any part of the 
surface of the body the flow of current is not in one but 
in every direction, and therefore there can be no definite 
direction of the flow in the muscle under treatment, the 



effects being effects of pole and not effects of direction 
of current. However, with the indifferent electrode 
central, and the active one peripheral, it is permissible 
to speak of treatment with descending currents when 
the active electrode is the kathode, and of ascending 
currents when it is the anode ; the words ascending and 
descending having reference to the general direction 
from anode to kathode, and not implying any theory of 
the physiological or therapeutical importance of the 
direction of the flow at the seat of disease. 

150. Methods. — Most electrical treatment is now 
carried out by using a single active electrode, and an 
indifferent electrode. The active electrode may be 
three, four, or five, or more centimetres in diameter 
according to the extent of surface to be included in the 
treatment, and the magnitude of the current used ; the 
electrodes must be well moistened with warm water, 
the indifferent one in its sheath is then pushed down 
the back of the neck for patients who are dressed and 
sitting up, or it is placed under the hips for patients 
lying down. The part to be treated is then bathed with 
warm water, and the active electrode applied, and the 
current slowly raised to a proper strength ; with the 
battery current three, five, or ten milliamperes or more 
if necessary. The active electrode is then moved 
slowly over the whole of the affected part {labile method) 
or it is kept still in one place {stabile method), or the 
circuit may be closed and opened for the sake of pro- 
ducing muscular contractions, or may be even reversed 
by means of a commutator, for the same purpose. 
These reversals are especially powerful in exciting 
muscular contraction. 

It is sometimes useful to have the indifferent elec- 
trode also in the neighbourhood of the part under treat- 


ment ; by doing this the current can be concentrated 
through the part tested. 

In testing or treating the muscles of the hand for 
instance, it is often convenient to lay the indifferent 
electrode under the palm while the dorsum is being 
treated and vice versa. 

Sometimes too a bowl of water is useful as a medium 
between the electrode and the patient, who may dip a 
hand into the water in which one electrode is placed, 
and have the other electrode at the nape of the neck, 
or he may have two such bowls of water and put one 
extremity in each, when the current is to traverse two 
limbs at once. Treatment with the limb immersed in 
a bath in which the electrodes are suspended will be 
considered in the next chapter under the heading of the 

When sensory impressions are chiefly desired, the 
skin is treated dry with a metallic brush of very fine 
wires ; a long secondary coil of many turns is most 
suitable for use with this. 

The induction current is to be employed where tonic 
or stimulating effects are chiefly desired, and with this 
object it is valuable in the treatment of paralysis and 
anaesthesia. Where the involuntary muscle requires to 
be roused, the battery current with interruptions and 
reversals is probably more effectual ; thus the abdomen 
and the rectum may be treated for constipation, and the 
bladder or the uterus for atonic conditions. 

Reference to the chapter on diagnosis explains the 
methods for testing the individual muscles and nerve 
trunks ; their treatment consists usually in moving the 
wet surface of the electrode slowly over the moistened 
skin covering the muscles with a sliding and a rolling 
movement. This sliding movement is a guide to the 


proper degree of moisture necessary. If either the skin 
or the surface of the electrode be too dry the latter will 
not slip smoothly, but will seem to stick, or move 
harshly. When this is felt the electrode must be 
moistened afresh. A little soap rubbed on the elec- 
trode makes it glide well. 

It must not be assumed that the degree of benefit 
from treatment can be measured by the amount of 
visible contraction of the muscles, for in addition to the 
exercise so produced there are vaso-motor effects, and 
reflex effects through the centres in the cord, both of 
which take part in bringing about the final results. 

The duration of each application should be about ten 
minutes, and this time must be distributed over the 
muscles or other parts needing treatment. When the 
dry brush and painful currents are employed, five 
minutes will usually be quite long enough, and the 
patient must on no account be reduced to a state of 
exhaustion from over-treatment. The operator should 
always try the current by experiment on his own 
muscles, in order to know exactly what amount of dis- 
comfort or pain his patient is called upon to bear. 

151. '^General faradisation/^ — We can now con- 
sider the methods of general treatment. The old plan 
of treating patients by means of metallic electrodes 
placed in the two hands may be regarded as a rude 
attempt at general electrification. Drs. Beard and 
Rockwell have elaborated a method of " general faradi- 
sation," the advantages of which they claim to have 
been the first to bring before the notice of the medical 

The object aimed at is "to bring every portion of the 
body in turn under the influence of the treatment so far 
as is possible by external applications." 


They consider that this is best accompHshed by 
placing one pole of the induction coil under the feet or 
gluteal region while the other is moved over the general 
body surface. The patient should stand or sit upon the 
surface of a large metal electrode covered with moist 
flannel, this must be kept warm by means of a hot 
water bottle or some other contrivance, as the treat- 
ment lasts for from ten to twenty minutes. The other, 
active, electrode is then to be moved over the various 
parts of the body, two or three minutes being given 
to the head, neck, back, abdomen, arms, and legs, in 

The application to the limbs is less important, and 
may be omitted in certain cases. 

The details which follow are given for reference in 
cases where the electric bath cannot be used. Where 
an electric bath exists general faradisation of this kind 
will not be needed. 

The active electrode should consist of a metal disc 
or ball covered over by a large sponge of six inches in 
diameter, and kept moist with hot water. The object 
of using electrodes of large size is that by their means 
the current is rendered less painful, and consequently 
the patient can bear stronger applications ; the use of 
the operator's hand as the active electrode''' is also 
recommended by Dr. Beard as its tactile sensibility 
makes it easy for the operator to gauge both the amount 
of pressure he is employing, and also the force of the 
current used. When the hand is to be used as the 
active electrode the operator should put himself in the 
circuit by holding the wet sponge in his other hand, the 
current then passes through his own body from hand to 

* This mode ot application is spoken of as the " electric hand," or 
the " hand electrode." It was employed by Duchenne. 



hand and so to the patient. He can vary the force of 
the current by altering the degree of pressure with which 
he holds the sponge, for when it is firmly grasped the 
current passes more readily and is increased, and when 
the grasp is relaxed the current is diminished ; no bad 
results follow to the operator, on the contrary he shares 
with his patient the benefits of the treatment, and con- 
siderable development of the muscles of the arms is said 
to follow. 

The patient may be seated while the upper part of 
the body is under treatment, but should stand up if 
possible for the application to the hips and thighs. A 
loose garment like a shirt or night-gown can be worn, 
or a large shawl or blanket may be thrown round the 
patient. The electrode can then easily be manipu- 
lated and moved over the surface of the body without 

In the region of the head the forehead and the vertex 
are the most important ; if the hair is at all long or 
thick it may be moistened, to diminish its resistance. 
The treatment of the back of the neck and the whole 
region of the spine is considered to be extremely impor- 
tant and should be thoroughly carried out, the electrode 
being slowly moved up and down along the whole 
length of the back. 

The sensations felt by the patient should be of an 
agreeable nature, a pleasant thrill, without any sort of 
pain or discomfort. The operator must bear in mind 
that the sensibility of the surface varies in 'S^ifferent 
parts of the body and he must adapt the force of the 
current to suit such variations, using the hand by pre- 
ference for treating those parts which are most sen- 

The results of the treatment are mainly tonic in their 


nature, a feeling of vigour follows, depression or fatigue 
are relieved, the appetite is increased, the patient sleeps 
more soundly, there is an increase in the firmness of the 
muscles, and an improvement in the circulation. In 
some patients these results follow promptly, in others 
their development is more gradual ; the same variability 
in the response of patients to other forms of electrical 
treatment has been observed by others. 

The treatment should be carried out two or three 
times a week, or every other day. Currents sufficiently 
strong to cause muscular contraction should be em- 
ployed, as soon as the patient has become accustomed 
to the treatment and is able to bear them without 

The process just described is doubtless useful, but 
there is a decided risk of the patient being chilled. The 
electric bath produces the same results with more com- 
fort to the patient and should entirely supersede the 
above described process whenever it can be arranged. 

152. Galvano- faradisation. — Dr. de Watte ville 
has recommended the simultaneous use of the con- 
tinuous and the interrupted currents under the above 
name. The method consists in " uniting the secondary 
induction coil and the galvanic battery in one circuit by 
connecting with a wire the negative pole of the one with 
the positive of the other, attaching the electrodes to the 
two extreme poles and sending both currents together 
through the body," we are told that "the effects of the 
faradic current are greatly enhanced by a simultaneous 
galvanization, because the points upon which the stimu- 
lus falls are in a state of exalted excitability or kath- 
electrotonus. Owing to the ' refreshing properties ' of 
the galvanic current upon muscle, the fatigue and ex- 
haustion which might otherwise be the consequence of 


energetic faradisation are avoided." Dr. De Watteville 
has a very high opinion of the advantage of this mode 
of treatment, particularly for electrisation of the abdo- 
minal viscera, and in rheumatic conditions, and in 
atrophic paralysis. The method is still occasionally 

The strength of each component may be about the 
same as when either is being used alone. 

153. Central §^alvanisation. — This is a plan of 
applying electrical currents to the nerve centres, also 
introduced by Drs. Beard and Rockwell. It consists 
" in placing the negative pole at the epigastrium, while 
the positive pole is applied to certain parts of the head 
(chiefly the vertex and forehead), to the sympathetic 
and pneumogastric in the neck, and down the whole 
length of the spine from the first to the last vertebra." 
It is said to be useful in cases of hysteria, neurasthenia, 
sleeplessness, dyspepsia, and other complaints. The 
duration of the treatment may be about ten minutes, 
and the position of the negative pole should be changed 
a little from time to time, to prevent any electrolytic 
effects upon the surface of the skin beneath it. The 
strength of the current should be varied between five 
and ten milliamperes, according to the part under 
treatment, and may be reduced to two or three milli- 
amperes for the applications to the skull if the patient 
appear to be very susceptible. 

Among recent writers upon central galvanisation Dr. 
Armstrong''' of Buxton may be mentioned. In his 
paper he advises currents of one to five milliamperes 
for the head and up to twenty milliamperes for the 
spine, with sittings of ten to thirty minutes repeated 
three or four times a week, or daily. He quotes cases 
* Transactions of the Royal Medical Society of London, vol. xxi. 


in which he obtained good results in palpitation and 
irregular action of the heart, in exophthalmic goitre and 
in conditions of cerebral exhaustion and in neurasthenia 
and enumerates among the good effects obtained that 
the patients treated had improved appetite and diges- 
tion, spoke of feeling brighter, their bowels were more 
regular in action, and they slept better. He mentions 
that with currents of too great strength, or too abruptly 
made and broken, unpleasant effects may follow, especi- 
ally in the applications to the brain. He does not 
insist upon the epigastric position of the indifferent 
electrode so strongly as is done by Beard and Rockwell. 

Electrical applications to the nerve centres will pro- 
bably be found useful in many cases of the kinds just 
mentioned. Patients to whom I have given treatment 
to the sides of the head for affections of the auditory 
apparatus have on several occasions volunteered the 
statement that they found the treatment had a good 
effect upon their general health, and Capriati''' has 
recently shown by a series of careful experiments with 
healthy individuals that the application of currents 
(stabile) of ten to fifteen milliamperes to the spine for 
ten minutes, produces a marked effect upon the mus- 
cular power of the individual, and one which lasts for 
several hours or days after the application has ceased. 

It is probable that a more extended course of obser- 
vations upon the influence of spinal and cerebral elec- 
trification in disease would give encouraging results 
particularly in functional conditions, and possibly m 
many neurasthenic states. The battery current must 
be employed, as that of the induction coil does not 

* Influence de I'electricite sur la force musculaire. Arch, d^electri- 
cite medicale, November, i8gg. See also Leduc, same Journal, 
May, i8gg. 


penetrate so well to the deeper parts of the body. The 
choice of pole does not appear to have any decided 
influence, although Rockwell expresses a preference 
for the positive pole as the active electrode. 

154. Galvanisation of the cervical sympathe- 
tic. — This procedure was much recommended at one 
time, but it is not clearly proved that the cervical 
sympathetic has ever been appreciably influenced by 
electrical treatment. At least none of the ordinary 
physiological eff'ects on the pupil or the blood vessels 
of the head and neck of stimulation of the sympathetic 
are produced. The treatment is carried out by placing 
one electrode below the ear and the other at the nape 
of the neck, and passing a weak current. All sorts of 
advantages have been claimed for this method, which 
has become an established part of the routine treatment 
of many morbid states of the central nervous system, so 
that in Erb's opinion it should be carried out "in every 
case where it is hoped to act on the circulation and 
nutrition of certain parts of the brain." Dr. Moritz 
Meyer's plan is to place a medium sized electrode at 
the angle of the jaw, with its surface directed back- 
wards and upwards towards the vertebral column. 
The other pole should be larger, and applied to the 
opposite side of the back of the neck, on a level with 
the fifth, sixth, or seventh cervical vertebra. The 
kathode is usually placed in front, but not always ; the 
current should be two to five milliamperes, and the 
duration one to three minutes, the application stabile. 
In certain cases both sides may be treated successively. 
As this treatment must involve all the other important 
nervous parts of the neck and the base of the skull, as 
well as the cervical sympathetic, it would be better to 
adopt Dr. De Watteville's suggestion, and speak of 


suhaiival galvanisation, rather than of galvanisation of the 

155. Self-treatment by patients. — It is a matter 
of the greatest importance that all electrical treatment 
should be carried oat by the medical man himself 
whenever this is possible, and if it is not possible for 
him to do so, then at least he should supervise the 
treatment as often as he can. Except in the very 
simplest applications of electricity, the results when 
patients are left to themselves with a battery, are 
generally unsatisfactory, and the usual consequence is 
to bring electrical treatment into undeserved discredit. 
It would be very nearly as reasonable for a patient to 
attempt to act as his own dentist as for him to try to 
cure himself by means of a battery without full medical 
advice and constant supervision. Only those who use 
batteries regularly are able to deal with the difficulties 
of making them work properly, and it is therefore 
absurd "^ to place one in the hands of a patient who 
cannot even know whether it be working properly or 

An exception may be made in favour of treatment by 
the mduction coil v/hen a long course is necessary for 
.a particular case. The manipulations may then be 
carried out by a trained nurse provided she be given at 
the commencement of the case a few careful lessons 
in the anatomy of the part to be treated, and in the 
manipulations to be performed ; she must be supervised 
at frequent intervals by the medical man in charge of 
the patient, who should never omit to make measure- 
ments and tests from time to time, to ascertain what 
progress is being made, and to prevent the case from 
being left in the sole charge of the nurse. 

So too with the treatment of infantile paralysis by 


means of a coil and bath-tub applied daily at bedtime ; 
it is impossible for the medical practitioner to see to it 
during the whole period of treatment, and one person, 
the nurse or mother, must be carefully shown what to 
do for the particular case, but the periodical testing by 
the medical man himself must not be omitted. Other 
conditions treated by the arm-bath methods (see 
Chapter X.) may also be left to be carried out by the 
patient if he be properly instructed in the first place, 
and supervised from time to time afterwards. 

Another simple electrical application which an intelli- 
gent patient can be taught to do for himself is the 
treatment of tmnitus and nerve-deafness (which see). 
The expense of electrical treatment when it has to be 
applied daily for long periods by a medical man may 
prevent the patient from giving the treatment a fair and 
prolonged trial, and on this account it is sometimes 
desirable to teach the patient what to do and to let him 
do it for himself. This is particularly the case in 
chronic conditions w^here a successful result from the 
electrical treatment cannot be predicted with certainty. 
The aid of electro-therapeutic methods is often invoked 
only when every other treatment has been tried without 
success, and thus it happens that many cases have 
already become chronic and difficult to move before 
they come for electrical treatment. Moreover the mode 
of action of electricity upon the tissues of the body is in 
its essence a gradual one, working as it does by a slow 
rebuilding or regeneration of the damaged organ or 
function, and requiring time and the exercise of patience 
and perseverance in its applications. It is among the 
poor and in hospital patients that one has the best 
opportunities of seeing the good which can be done by 
electrical treatment in chronic cases. In that class of 


patient considerations of expense do not interfere to cut 
short the treatment prematurely, nor do they so readily 
throw up one kind of treatment in order to try some- 
thing different. Thus it is a not uncommon experience 
of mine to have similar cases under treatment at the 
same time, the one at the hospital and the other as a 
private patient, and to see the latter grow restive and 
give up treatment when half through with it, while the 
former goes steadily on and makes a good recovery. 

Nevertheless, in spite of what has just been stated, 
there is no doubt that the proper person to carry out 
electrical applications is a competent medical man, and 
that should be the rule wherever possible. To hand 
patients over to nurses and masseurs for electrical 
applications is to give away to outsiders a valuable 
means of relieving patients which should obviously be 
kept entirely in the hands of the medical practitioners 



The Electric Bath. 

The bath. Accessory apparatus. The resistance of the bath. The 
mode of application. The use of the electric light mains. Hot 
air or vapour electric bath. Uses in chronic rheumatoid 
arthritis. Gout. Sciatica and lumbago. Nervous affections. 
Rickets. Anaemia. Raynaud's disease. 

156. Advantages of the electric bath. — The 

electric bath is used in the treatment of morbid con- 
ditions which affect the whole system, because it pro- 
vides a convenient and agreeable way of applying 
general electrification, a mode of treatment of great 
value whenever general stimulating, and tonic effects 
are required. 

The publication of Duchenne's classical work De 
V electrisation localisee, which gave so great an impetus to 
systematic electrical treatment, tended also to produce 
the impression that electricity was useful only in ner- 
vous diseases, and that local applications to the affected 
nerves and muscles formed the only plan of electrical 
treatment worth following. 

General electrification, however, has a very powerful 
trophic influence upon the body, and is most useful in 
the treatment of many morbid states, such as debility, 
anaemia and chlorosis, rickets, rheumatism, rheumatoid 
arthritis, gout, sciatica and lumbago, and generally in 
diseases due to impaired and defective nutrition ; also 
in general neuritis after diphtheria, influenza and other 
toxaemic conditions. 


General electrification carried out by means of an 
electric bath is agreeable to the patient, and far more 
efficacious than the process of " general faradisation " 
or of " central galvanisation " referred to in the last 

The advantages of using a bath of water as a means 
of conveying electricity to a patient are as follows : — 

First, the water provides the best of conducting 
media because it adapts itself so completely to the 
surfaces of the body. Secondly, because by moistening 
the skin uniformly and thoroughly, it lowers its resist- 
ance and favours the comfortable passage of the current 
through the skin. 

Thirdly, all parts of the body are brought under 
treatment together, and this simplifies matters both 
when the body as a whole is to be treated, or when, as 
in rheumatoid arthritis, there are a number of separate 
areas all requiring attention. 

Fourthly, because the warm water serves to keep the 
patient warm and comfortable during the time of the 
application. We may also mclude the stimulating 
action of a hot-water bath upon the skin, for this is an 
additional therapeutic means that may often be of 
service in the cases which are being treated by elec- 
tricity. For instance, lead poisoning is greatly bene- 
fited by electrical treatment, and also derives benefit 
from hot baths, so much so that a course of the Bath 
Waters was at one time a recognised treatment for cases 
of lead poisoning. In infantile paralysis too a hot 
bath given daily is a very useful therapeutic application 
and can be combined very advantageously with the 
electrical treatment. 

It is unfortunate that the electric bath has been taken 
up of late by unscrupulous persons, and so has been in 


danger of falling into discredit with medical men. From 
its manifest advantages it deserves a better fate. 

157. Apparatus and methods. — The bath itself 
should be made of porcelain or earthenware, or it may- 
be made of wood. The former is the best, as it is easily 
kept clean and is nice looking. 

A bath live feet six inches in length is better than 
one which is six feet long. 

The water in the bath should be agreeably warm, 
averaging 99° F., but it may be slightly warmer or 
cooler to suit the wishes of the patient. It is note- 
worthy that a difference of one or two degrees makes 
a great difference in the sensations of warmth felt by 
the patient at these temperatures. The bath should be 
so filled with water than when the patient lies in it the 
whole body and the shoulders may be covered. A bath 
thermometer must always be used to ascertain and 
regulate the temperature. 

Two electrodes in the form of metal plates placed 
at the head and foot of the bath are required, and they 
should always be kept clean and bright. These metal 
plates are provided with binding screws to which the 
battery wires are attached (fig. 70). The best metal 
is copper. Zinc plates may also be used. It is no use 
having these metal sheets plated, as is sometimes done 
for appearance sake, for the plating quickly leaves the 
positive pole. The electrode placed at the head of the 
bath is usually the larger, and may measure eighteen 
inches by twelve, that at the lower end of the bath 
being eleven inches by nine. When it is wished to 
localise the current more or less in any part, a move- 
able paddle, two or three inches square, connected to 
the plate at the foot of the bath, may be used for this 
purpose. It may be used either to supplement the foot 



plate or to replace it. The water should always be 
deep enough in the bath to cover the plates. 



Fig. 70. — Electrodes for the bath. 

The shoulders and back of the patient are kept from 
touching the plate at the head of the bath by a rest 
made of wood, something like a picture frame having 

Fig. 71. — Back rest. 

pieces of webbing stretching across (fig. 71). The light 
wicker fire screens which are made to fit on to the 
backs of chairs are also very convenient and comfort- 


able for the purpose. Though rough to the hand when 
new they soon become softer and do not hurt or scratch 
the back ; with female patients the bathing dress gives 
additional protection. 

The feet may be allowed to touch the electrode at 
their end of the bath because the epidermis on the soles 
is thick enough to take care of itself. If a patient 
prefers it, the feet need not be placed in actual contact 
with the metal, but they should be kept in close prox- 
imity to it. The arms must be extended if they are to 
share in the treatment, and folded if the current through 
them is to be kept small. A part only of the total 
current in circuit traverses the body, the remainder 
passing through the water in which it is immersed. 
The w^ater in the bath offers a broad conducting 
medium with a large transverse sectional area, several 
times larger than the patient and therefore a consider- 
able part of the current traverses the water and is alto- 
gether lost to the patient. 

The electric bath was installed at St. Bartholomew's 
by the late Dr. Steavenson in 1882, and was for many 
years the only electric bath at a London hospital. 
Recently, as I am informed, one or two other hospitals 
have recognised their advantages and have taken them 
into use. The bath method of applying electricity has 
further been extended by the introduction of arm-baths 
and foot-baths as well as the large general bath ; so 
that there are now at St. Bartholomew's Hospital five 
of these small baths in regular use, to the great advan- 
tage of many patients, and with the effect of greatly 
simplifying the process of treatment ; better results are 
now obtained in many conditions of disease by bath 
methods than was formerly the case, when treatment 
was carried out by the tedious manipulations and 


rubbings of the patient's limbs with small hand elec- 

158. The resistance of the bath. — The resistance 
in an electric bath will vary with its length, with the 
depth to which it is filled, and with the temperature of 
the water. 

Dr. Hedley" has contributed largely to our know- 
ledge of the physics of the electric bath, and his book 
should be studied by all those who are interested in 
the subject. He has given the following figures as 
determined for a particular bath, six feet long, made 
of oak : — 


Height of water, 15 inches with body ... 162 ohms. 

JJ 5) 12 ,, ,5 ... 205 ,, 

10 „ without body ... 245 „ 
j> 5) 7 " " ••• 357 >j 

?? 55 5 " " • •• S-'-^ 55 

Resistance of bath with water at different tempera- 
tures : — 

Temperature. Resistance. 

98 Fahr. ... ... 165 ohms. 

92 „ 19+ n 

87 »» 264 „ 

In a second edition Dr. Hedley has worked out this 
question afresh, using a smaller bath and measuring the 
resistance under conditions more closely approximating 
to those which obtain in actual practice. He finds that 
in these circumstances the resistances may be consider- 
ably less than those quoted above. 

Another question of interest with the electric bath is 
the following : — How much of the total current passes 

* " Hydro-Electric Methods in Medicine." London, H. K. Lewis, 
1892. Second edition, 1896. 


through the patient, and how much is conveyed by the 
water ? The answer will depend upon the temperature 
of the water, and upon the volume of w^ater in the bath ; 
the problem is best attacked by regarding the condition 
as one of a divided or branched circuit ; the water 
being one and the patient the other of two conductors ; 
the proportion of current traversing each will depend 
upon their relative resistances. Moreover the thicker 
parts (trunk) of the patient will convey more than the 
average, and the thinner parts (limbs) less, so that one 
cannot say that the patient carries such and such a 
fraction of the total. Dr. Hedley,''' who has made a 
special study of the problem, suggests that under usual 
working conditions it will be safe to say that the 
average current passing through the immersed body 
is about twenty-five per cent, of the total current 
running through the bath, that the maximum, through 
the trunk, is probably nearer fifty per cent, whilst at the 
ankles, a part of the body where the sectional area is 
very much less than that of the trunk, the current may 
be about four per cent, of the total. 

M. Meylanf has contributed some experimental data 
upon this question. He measured the resistance of 
a bath first with a patient immersed ; secondly wdth 
the patient removed, the water as before ; and thirdly 
with the patient removed, but with water added to 
bring the level up to that which it had when the patient 
was in it. 

The measurements were as follows : — 

A. Water and patient ... ... 136 ohms resistance. 

B. Water only ... ... ... 156 ,, ,, 

C. Water, with water added ... 138 ,, ,, 

* "Therapeutic Electricity," J. A. Churchill, London, iSgg. 
t Revue internationale d''electncite, .Nov., 1894. 


By calculating out these figures we arrive at 1060 
ohms as the patient's resistance, and 736 ohms as that 
of the equivalent bulk of water added in experiment C* 
The resistance of the patient compared to that of his 
own volume of water spread out in a layer over the 
area of the bath was roughly as 4 is to 3. The cubic 
measurement of an average sized man is three cubic 
feet or about eighteen and a half gallons. 

If we compare the resistance of the water only, 156 
ohms, with that of the patient, 1060 ohms, we find that 
under the conditions of the particular bath, the patient's 
body was carrying about one-eighth of the current. 

As the current which traverses the water does not 
affect the patient and therefore may be considered as 
wasted, it follows that for economy of current the 
amount of water used in the bath should be no more 
than enough to cover the patient comfortably. On the 
other hand a large volume of water retains its heat 
better for the time required for the bath. 

If salt or acid is added to the bath, the water be- 
comes a better conductor than before, and the patient's 
share of the total current passing will be reduced. It 
is therefore useless and objectionable to make such 
additions to the water. In spite of this fact, some 
writers have advised it to be done. 

159. Choice of current. — The direct current, the 
interrupted current of the induction coil or the sinu- 
soidal current of an alternate current dynamo may be 
used in the bath. " Galvano-faradisation " (§ 152) has 
also been recommended. 

Of these the first is specially indicated for the treat- 
ment of painful conditions where the coil current or the 
sinusoidal current is not well borne. Thus the "gal- 
vanic bath " is useful in the earlier stages of alcoholic 



neuritis, in neuralgias and in acute sciatica. Again, 
where an effect on joints or other deep-seated parts is 
hoped for, as in rheumatoid arthritis, gout and rheuma- 
tism, the galvanic bath may be preferred. It has also 
been recommended in degenerative states of the spinal 
cord where irritative symptoms are present, as for 
instance in chronic myelitis, progressive muscular 
atrophy, in lateral sclerosis, and in tabes. A few cases 
have been published where these conditions have 
seemed to be benefited in this way. The vast majority, 
however, have received no benefit, and it is still quite 
uncertain whether anything can be hoped for in the 
future from the electrical treatment of these progressive 
spinal cord diseases. Hitherto, it must be confessed, 
we have not discovered how to apply it for their cure, 
so that one is almost tempted to believe that the few 
cases which have been recorded as successful may have 
been misinterpreted. 

It must be borne in mind that the bath plays a quite 
secondary part in electrical applications, and that it is 
valuable rather as a convenient mode of bringing the 
current to the patient than as having special therapeutic 
qualities of prime value, so if in the future an electrical 
method of influencing these degenerative spinal diseases 
should be discovered it would then be time enough to 
consider whether the applications could be advan- 
tageously carried out in a bath or not. The line along 
which there is most promise of future possible success, 
is with the direct battery current applied to the region 
of the spine, and for this the use of the bath does not 
seem specially indicated, because the spine can be easily 
reached and treated without it. 

The induction coil bath and the sinusoidal current 
bath are indicated where simple nutritive effects are 


required. Debility of all kinds, chlorosis and other 
forms of simple anaemia, peripheral paralyses and 
infantile paralysis (except where recent or acute), the 
later stages of transverse myelitis, neuralgia, lumbago 
and sciatica, except when acute, and rheumatism and 
rheumatoid arthritis are all greatly relieved by the 
electric bath with coil or sinusoidal current. The 
physiological effects of both forms are similar ; the 
differences between them are chiefly in the greater 
smoothness of the latter and the larger currents which 
can be borne with it. It is a less sharp stimulus to 
nerves and muscles. In all cases except one the sinu- 
soidal current of a dynamo is to be preferred if it can 
be obtained, but in its absence the current of the coil 
may be used in its place. 

For stimulating the muscles of the trunk, and especi- 
ally the abdominal muscles, the sharp pulses of the 
induction coil are the best ; thus the coil is to be 
preferred when one is asked to give electric baths to a 
patient with constipation, or with flaccid abdominal 
walls and pendulous belly, or in ascites. In this latter 
condition electrical treatment often gives good results, 
as will be instanced later. 

In many skin diseases electric baths act very effi- 
ciently, and the use of water as the electrode is 
especially happy in such conditions in which the 
rubbing of the sore surface with leather-covered elec- 
trodes is quite unsuitable. 

An interesting point which has been often observed 
both with direct and with sinusoidal baths, is that acne 
of the back disappears during a course of bath treat- 

160. Direct current from the mains. — The elec- 
tric lighting mains (direct current) may be used for the 

u 2 


electric bath. The current may either be used to 
charge accumulator cells which are then completely 
detached from the charging circuit and used for the 
bath, or the current of the mains may be connected 
directly with the bath itself. 

A practical point of great importance in such pro- 
ceedings is the great leakage to earth from the con- 
ductors of the continuous current supply systems. The 
complete insulation of a bath which is even indirectly 
in relation with water supply-pipes and waste-pipe is 
almost impossible. 

It is troublesome, and is very likely to fail at an 
inopportune moment. On a circuit of 100 volts this is 
bad enough, but with 200 volts or more between one 
conductor and earth it would be very serious. The 
tendency towards 200 volts systems of supply and the 
use of the three wire and five wire systems increase the 
difficulty of dealing with the leakage to earth. 

In my opinion no method which depends for its safety 
upon the maintenance of the insulation from earth of 
a bath containing water is good enough to risk, and it 
is therefore best not to attempt to insulate the bath, 
but on the contrary to have it thoroughly well earthed. 
Its metallic water-pipe connections generally suffice, 
but to make sure the cold-water pipe can be joined by 
a soldered-on wire to the waste-pipe. The bath may 
then be given, the leakage to earth being allowed for 
and the voltage regulated by resistances in series with 
the bath, and fixed at both ends of the bath because the 
patient would in no wise be protected from discharges 
to earth of serious magnitude by a resistance placed on 
only one of the two conductors of the bath. Or the 
method of a shunt circuit to provide a slope of poten- 
tial which can be tapped as desired (§ 68) may be used, 


provided that the safety lamp (B, fig. 22) be chosen of 
a proper resistance. 

In all electric bath treatment the utmost care must 
be taken with the conducting circuits and the regulating 
apparatus. The least neglect of the connections, both 
at binding screws and especially at the sliding connec- 
tions which have to do with regulating and varying the 
strength of the current, is likely to lead to annoyance 
and the loss of patients. The patient in the water is 
so completely helpless that he may justly be alarmed 
at the occurrence of anything unexpected in the flow 
of current, and he may consider it to be dangerous to 
come for any more treatment if he has once received 
a disagreeable shock. A loose wire end in a binding- 
screw or a conductor broken inside its coverings of 
insulation may be enough to give trouble in this way. 
Servants can never be trusted to see to connections 
properly. They do not know enough, and think nothing 
of screwing up the end of a wire, insulation and all, 
in a binding-screw. For myself 1 follow a rule of 
always making trial of the entire bath circuit at the 
last moment before the patient steps into the water. 
It is never safe to omit this precaution, and it is use- 
less to think of it when the patient is already in the 

161. The sinusoidal current.— This is the form of 
bath which has been most studied and used in recent 
years. Its employment has been made easy in many 
places by the systems of alternate current electric light 
supply which are now fairly common. For general 
purposes it is the best kind of electric bath to give. At 
St. Bartholomew's it has been very largely made use of 
for several years, and has entirely replaced the induc- 
tion coil bath, and partially the direct current bath. 


In the absence of alternating current mains a small 
dynamo can be used to generate the current, and may- 
be driven by a water motor, or by a continuous current 
motor worked by a battery of accumulators or by the 
direct current mains if they are available. The instru- 
ments figured in § 71 p. loi are well suited for this latter. 
There may be leakage to earth, and so to the bath, of 
the direct current driving the machine. To guard 
against this and at the same time to regulate the 
strength a small adjustable transformer (§ 70) is the 
best instrument, and the same form of appliance is 
wanted with the alternating electric light mains. A 
proper voltage for the sinusoidal bath is between four 
and eight volts, with an average of six. 

A sledge induction coil may be used as a regulating 
transformer if the screw of the contact breaker be 
screwed down tightly so that it cannot vibrate. It 
must be made quite tight, or better it may be removed 
and the connections made directly to the ends of the 
primary. The secondary coil can then be used as the 
source of the current for the bath. The only precaution 
necessary is to avoid overheating the coil by applying 
too great a voltage to the primary. Off the 100 volt 
mains a lamp of eight candle-power must be arranged 
in series with the primary (see fig. 25). 

162. The mode of administration. — The battery 
current for a bath must be very gradually raised until 
the galvanometer registers 100, 150 or 200 milliamperes, 
but it is best for the first few baths to use a current 
not exceeding 100 milliamperes. A battery of large 
Leclanche cells answers very well ; thirty of these or 
twenty accumulator cells may be connected with a 
switch board having a double or single collector (§ 80) 
and a commutator (§ 81) ; a galvanometer graduated to 


read up to 250 milliamperes must be included in the 

The induction coil hath. — For a coil bath a coil with a 
secondary of few turns is best, because the magnitude 
of current is relatively large, and the volts needed are 
small (p. III). In those coils which are tapped in such 
a way that either a part or the whole of the total turns 
can be used, it is generally better to use the part than 
the whole coil. Regulation can best be carried out 
with a coil of sledge pattern (fig. 32). The paddle 
electrode, § 157, may be used. If it is brought near to 
the abdomen brisk contractions can be set up in the 
abdominal muscles. 

The patient after entering the bath should be allowed 
a minute or so to recover from the reaction produced 
by the warm water before the current is turned on. 
The current should be increased slowly and cautiously, 
and the galvanometer watched, and at the termination 
of the bath the current must be reduced as slowly. The 
direction of flow should generally be from the head to 
the feet, the anode being at the upper end of the bath, 
and the kathode at its foot. There is no certain know- 
ledge of the effect of the direction of flow in treatment 
by the constant current bath, but the direction here 
given represents the views of the late Dr. Steavenson, 
for the treatment of electric bath cases. A medical 
man should always be present to regulate, increase, or 
diminish the strength of the current. The patient can 
wear an ordinary bathing costume. With female 
patients the presence of a nurse or a maid is necessary, 
but the medical man should also remain in the bath- 
room while the current is flowing. As the current is 
slowly augmented the first sensation experienced by the 
patient is usually a slight pricking or tingling at the 


ankles or at the knees. A metallic taste may be per- 
ceived as the current becomes stronger. Should the 
patient's head feel full or throbbing during the adminis- 
tration of the bath a cold wet towel may be placed on 
the top of the head. And if any faintness is caused, 
the current must be reduced. An electric bath must 
not be taken too soon after a full meal. After the bath 
the skin of the back near to the upper electrode will 
be found of a bright red hue, this will gradually pass 
off in an hour or two. After dressing, the patient 
should rest for ten or fifteen minutes before going out 
into the open air, and should walk home if able to do 
so. After an electric bath the patient generally leels 
exhilarated and better. Should there be any sign of 
languor or depression after a bath, currents of small 
magnitude should be employed. 

It is usual for patients to feel a little inclined to sleep 
some hours after a bath, and it is as well to tell them 
of this beforehand or they may take it as an unfavour- 
able sign. 

After the bath it is best that the patient shall dress 
slowly in order to allow the activity of the circulation 
in the skin to diminish during the process of dressing. 
If this is not done there is a risk that the skin will 
perspire sensibly and that the patient will feel damp 
and uncomfortable, and will run the risk of taking a 
chill. With due care there is very little danger of cold 
after an electric bath. Among the very numerous 
patients who come to the hospital for electric baths 
throughout the year the taking of a cold afterwards is 
practically unknown. 

The duration of the bath should be for ten or fifteen 
minutes, and they may be given on alternate days. 
Twelve or fourteen baths are needed to produce a good 


result in most cases, and may be taken to constitute 
" a course." But in many chronic states more than 
this number will be wanted. 

163. Combined electric and hot air or vapour 
bath. — Electricity has been applied to patients when in 
a hot air or vapour bath. This form of application 
is said to possess certain therapeutical advantages. 
Patients who suffer from depression or are unable to 
bear the water electric bath may be able to take the hot 
air or vapour electric bath. The bath is given in a 
cabinet constructed for the purpose. The patient is 
seated or stands upon a surface connected to one pole. 
The other pole of the battery can be connected with 
special electrodes to be applied to different parts of 
the body. The cabinet contains a hot water coil. 

During the bath the operator applies the electrodes 
to that part of the patient's body which is to be 
treated. Sometimes a projecting metal arm is used 
with the end covered by sponge against which the 
patient's back or epigastrium can rest. This projecting 
arm is fixed to the back or side of the cabinet and con- 
nected with one of the poles of the battery. 

A hot air or vapour electric bath is nothing more 
than the application of electricity to a patient whose 
skin is rendered a better conductor through the 
warmth and perspiration that is induced. The skin 
is softened and so rendered a better conductor. The 
vapour bath is considered more relaxing and sooth- 
ing than the hot air bath. Although the current is not 
conveyed by vapour or steam, it may be carried by an 
unbroken jet of water ; and douches can be contrived 
which will at the same time electrify a patient, if he 
stand or sit upon a conductor so as to complete the 


164. The electric douche bath. — In the Revue 
internationale d' eledr other apie for June, 1894, there is an 
interesting account by Dr. Guyenot, of Aix les Bains, 
of his method of applying electricity by means of 
douches. The current is led to and from the patient 
by two streams of water, the conductors being con- 
nected to the metal nozzles through which the water 
flows, and he insists upon the ease with which the jets 
of water can be made to carry the current to the whole 
surface of the body or to any part of it so as to give the 
effect of a general or of a localised electrification. 
Careful working details of the modes of applying the 
battery current or the induction coil current either 
local or generally, will be found in his paper, which is 
well worthy of attention. 

Of late years electrical applications have come into 
very general use in spas and health resorts, not only 
abroad but also in this country, and this speaks 
volumes for the superior advantages of electricity over 
hydrotherapy pure and simple. Electro-therapeutics 
also find a more favourable public at such places than 
they do in large and busy towns, for patients who 
cannot spare the time for a regular course of treatment 
when at home are able and willing to do so when stay- 
ing at a health resort, and detached from their daily 

165. The arm-bath. — The use of the bath method 
of applying electricity to the forearms and' hands or to 
the feet is often very convenient. Any non-conducting 
vessel to hold water may be used if of suitable size. 
Oblong stoneware troughs can be had which are exactly 
suited to take the hands and forearms, and Mr. Miller 
(93 Hatton Garden, E.G.) can supply them with elec- 
trodes already fitted. 


The best form of electrode is of sheet metal cut out 
in one piece in the shape of a tennis bat ; the handle is 
bent over into a hook and serves to hang the electrode 
from the end of the trough. It is flexible and can be 
bent to fit any form of trough or tub, and is fitted with 
a binding screw. 

The arm- bath is specially suited for cases such as 
paralysis of the muscles of the forearms and hands, 
as for example in extensor paralysis from lead poisoning 
or from pressure, in paralysis from various injuries to 
the nerves of the forearm, in rheumatic and gouty 
affections and rheumatoid arthritis affecting the wrist 
and finger-joints, in stiff wrists or elbows from injury 
or disease of those joints, in chilblains and Raynaud's 
disease affecting the hands, while the foot-bath is 
valuable for applications to the feet in the last- 
mentioned disorders. A consideration of this list will 
show how often the arm-bath is of service, particularly 
in general practice or in the electrical department of a 
hospital. Moreover the arm-bath greatly simplifies the 
process of applying electricity to a patient, by doing 
away with the tedious business of rubbing the elec- 
trodes over the affected parts. For these reasons the 
arm-bath is a most valuable method of applying elec- 
tricity and one which in my opinion deserves very 
general adoption by the profession. The constant 
current, the coil current, or the sinusoidal current may 
be applied in the arm-bath with equal advantage. The 
last-named is the most generally useful, except for 
joint affections. 

When a bath of any kind is so arranged that one 
electrode only is immersed while the other is directly 
attached to a portion of the patient which is not im- 
mersed, it has been called a monopolar bath as dis- 


tinguished from the ordinary or di-polar bath. A 
monopolar bath is not often necessary, it is mentioned 
here because it will be incidentally referred to later 
in this chapter. For a constant current arm-bath from 
9 to 12 cells may be used. In a trough-shaped vessel 
this will give a total current through the bath of from 
25 to 40 milliamperes. 

166. Chronic rheumatoid arthritis. — An affection 
for which the electric bath is most useful is chronic 
rheumatoid arthritis. Electric baths are valuable in 
all stages of the disease, and though they will not cure 
inveterate cases, they will do very much to arrest the 
progress of the disease, to reduce the pain and swelling 

Fig. 72. — Handle for rheumatoid arthritis. 

of the joints, and otherwise to produce great ameliora- 
tion in the symptoms. When the hands are chiefly 
affected a pair of metal handles of suitable sizes (fig. 72) 
covered with flannel may be employed to concentrate 
the current upon these parts. 

The handles are attached by conductors to that pole 
of the battery which is connected to the foot plate. 
The current is thus concentrated upon the arms and 
hands. But this local application of the current to the 
affected parts does not represent the whole purpose of 
the bath, nor is an arm-bath so good a method of 
treatment in this disease as is the general bath, which 
exerts an influence on the whole system. 


The hands may also be made to grasp a metal bar 
supported across the bath and covered with moistened 
flannel, the monopolar bath. In this position the hands 
are raised out of the water and carry the whole current, 
which must be adjusted to suit the altered conditions. 
When concentrated in this manner on the hands the 
patient cannot bear more than ten or fifteen milli- 
amperes. When changes in the direction of the current 
are to be made, the current must first be reduced to 
zero and then increased again. If the current were 
broken or reversed suddenly, the patient would receive 
a very unpleasant shock. This method is not so good 
as the general bath with concentration on the affected 
parts by the handles figured above. When the forearms 
and hands alone are affected the arm-bath daily may be 
used alone if no full length bath can be obtained. 

After the completion of a course of baths it is pos- 
sible to notice some improvement in the condition even 
of advanced cases. A patient for instance who could 
only climb upstairs slowly and painfully becomes able 
to make the ascent without assistance ; or a woman 
who could not hold her needle or perform her household 
work finds that she is able to do so fairly well. 

When the larger joints, such as the knees, hips, or 
shoulders, are the seat of rheumatoid arthritis, the 
current can be localised by the use of the small metal 
paddle (§ 157) placed in some position in the bath so 
as to concentrate the current upon the affected joints. 

Dr. Chauvet"' in a paper on the treatment of chronic 
rheumatism at Royat has recommended the arm-bath 
with lithium carbonate and reports fifteen cases treated 
in this way with currents of twenty or twenty-five 
milliamperes. He obtained good results in more than 
* Arch, d'electricite medicale, April, i8g8. 


two-thirds of the cases ; most of the remainder discon- 
tinued the treatment after a small number of baths and 
did not show any result. In the course of his paper he 
discusses the symptom known as Heberden's nodes, 
and is not able to say that he ever saw these disappear 
as a result of treatment. It is worthy of note that I 
have seen this year a patient in whom one of Heber- 
den's nodes has disappeared and others have softened, 
with great general improvement of the symptoms, dur- 
ing a course of induction coil arm-baths continued for 
six months. 

Gonorrhoeal rheumatism has also been treated by 
electric baths on the same plan as that followed in the 
treatment of rheumatoid arthritis, but not with quite 
such satisfactory results. 

167. G-out. — The electric bath is an excellent means 
of treating this disease, both for local applications to 
gouty joints and for combating the general gouty state. 
For the former the local arm-bath with the battery 
current is the best ; for the latter the general bath with 
the sinusoidal current is to be preferred. Good results 
have been reported by many observers with the arm- 
bath, and particularly when a solution of chloride of 
lithium has been used instead of plain water (see § 125). 
Guilloz* has reported two cases of severe and old- 
established gout which were successfully treated by 
local monopolar electric baths with lithium carbonate. 
He recommends large currents up to 200 milliamperes, 
the positive pole in the bath with the affected limb or 
limbs and the negative pole, of large size, applied to the 
back ; time of the applications from twenty to thirty 
minutes. The patients were also treated by auto- 
conduction (§110) and high frequency currents. The 
* Arch, cfelectricite medicale, June, 1899. 



first patient was twice treated for two severe attacks, 
each time with rapid good effect. The second patient 
also did well in spite of the fact that Dr. Guilloz says 
that he continued to follow a dietary which was " of the 
most detestable " and that his excesses in eating and 
drinking were renowned {^^ passent a Vetat legendaire "). 

168. Sciatica. — This is an affection well suited for 
treatment by the electric bath. Very good results are 
obtained by ordinary local treatment in this condition, 
but it is often more convenient and more agreeable to 
the patient to be treated by means of the bath, and the 
results are quite satisfactory. Some may respond 
quickly to the treatment, and some slowly, but all do 

From a very considerable number of cases of rheu- 
matism, rheumatoid arthritis and sciatica treated by 
the electric bath, I am of opinion that the induction 
coil current, or better still, the sinusoidal current, is as 
often useful as the battery current; indeed, I have 
sometimes found that the patient remained unimproved 
by the latter, and then began to progress favourably 
when the sinusoidal current was substituted for it. In 
other cases, I have known a patient improve under the 
constant current ; and, returning again a year later 
with the same symptoms, improve equally well under 
the other mode of treatment. It sometimes happens 
that the interrupted or alternating current increases the 
pain in sciatica, particularly in acute and recent cases. 
When this is the case the constant current acts more 
favourably, and may be applied directly by means of 
pad and electrode, or in the bath with the paddle 
brought near the affected region. It seems rather 
better to make the active electrode negative than posi- 
tive in this case. 


These conflicting experiences make it difficult to 
settle the question of the choice of current in these 
disorders. One might, perhaps, suppose that the im- 
provement under the alternating current was rather 
due to the indirect effect of systematic general stimu- 
lation, while the constant current might act by some 
direct local action, but it is better, in the present state 
of our knowledge, to be content to note the fact that the 
sinusoidal bath or coil bath may be successfully used 
in many conditions for which the continuous current 
bath has been recommended, and that the chief indica- 
tion for the latter is the presence of pain made worse 
by the alternating current. 

For the last few years I have used the alternating 
current of the electric light mains in most of such cases 
both at the hospital and in private practice, and have 
had better and more rapid good results than when using 
the constant current bath. The alternating current of 
the mains is therefore the form of current with which 
I am most well acquainted. 

The physiological properties of the sinusoidal current 
were first indicated by D'Arsonval, and their applica- 
tions to medical treatment have been made the subject 
of an interesting series of papers by Drs. Gautier and 
Larat.*^ This gives details of apparatus and short 
histories of twenty-seven cases. Among the more 
striking cases there mentioned is one of obstinate 
sciatica of two years' duration, which yielded after five 
baths, although previously rebellious to all kinds of 
treatment, including the constant current, the inter- 
rupted current, and electrostatic sparks ; and another 
of acute sciatica, which for six weeks had compelled 
the patient to keep his bed. He was completely re- 
lieved by the sinusoidal current baths in a week. 
* Revue Internationale d'electrotherapie, vol. iii. 


169. Nervous aflFections. — Much time has been 
spent over attempts to cure grave spinal cord diseases 
by electrical applications, but hitherto without success, 
and because electricity has failed in such things as 
tabes, progressive muscular atrophy, chronic myelitis, 
&c., it has been condemned by some as useless for any 
kind of treatment. At the same time it is very right 
and proper that electricity should be tried in this class 
of disorder, and it may be that some day a successful 
method of electrically influencing the nutrition of the 
spinal cord will be discovered. The direct treatment 
of the brain and cord have not been very fully worked 
out up to the present. 

The subject is introduced here in order to enable me 
to put on record some of my own work in spinal cord 
diseases by the sinusoidal current with the bath. 
During the past five or six years I have received for 
treatment at the hospital a certain number of cases of 
locomotor ataxy, of progressive muscular atrophy 
(Aran-Duchenne, Landouzy-Dejerine, Charcot-Marie 
types), of chronic myelitis, syphilitic and others, and 
have given them courses of baths during weeks or 
months, or even in some cases during years. I have 
never been able to satisfy myself of a single complete 
cure in any unequivocal case, although I have fre- 
quently thought that the progress of a case was tem- 
porarily arrested by the applications ; for instance 
patients have often returned after giving up treatment 
to ask for further treatment as they had lost ground 
after the discontinuance of the baths ; this especially in 
myopathic atrophies. A few cases of early or doubtful 
tabes have appeared to have been cured. One patient 
sent to me as pseudo-hypertrophic paralysis, and with 
symptoms closely resembling that disease, did recover 



completely, but the diagnosis was a little doubtful to 
my mind from the first. The class of cases above 
enumerated should therefore be considered unsuitable 
for treatment by general electrical stimulation. 

It is quite different with cases of functional or slighter 
diseases of the nervous system, with infantile paralysis, 
and with peripheral neuritis. Among these disorders 
there are many cases which derive great advantage 
from electricity, and they will be considered at greater 
length in succeeding chapters. 

The sequelae left by influenza, which sometimes 
produces symptoms of considerable mental and nervous 
failure, or even a definite neuritis with reaction of 
degeneration, are promptly relieved by the electric 
bath. I have had a number of these cases, and have 
seen them rapidly improve ; the same holds good for 
diphtheritic paralysis. In cases of severe alcoholic 
neuritis, the patients gradually regain power in the 
limbs and make good recoveries even after lying help- 
less for several months. The return of normal elec- 
trical reactions in the muscles of the legs may not take 
place until some time after the recovery of voluntary 
power, but in the end one will obtain normal electrical 
reactions and good development in the muscles which 
formerly showed wasting, paralysis, and a marked reac- 
tion of degeneration. Cases of cervical and brachial 
neuralgia, and neuritis in most of its forms, may be 
treated with great success by the electric bath or 

170. Metallic poisoning. — In patients with lead 
poisoning, treated by means of the bath or arm-bath 
with sinusoidal current, the results have always been 
most encouraging. Recovery is the rule, but three or 
four months of treatment may be required in severe 


cases. But among hospital patients who come in con- 
tact with lead during their work, the results are seldom 
very permanent, because they are apt to return to their 
occupation at the earliest opportunity, and so become 
poisoned afresh as soon as they have regained a little 
muscular power. 

In one instance a patient with lead palsy was treated 
with the battery current, and the electrodes of the bath 
were examined to see whether any electro-deposition of 
the metal could be brought about in the course of the 
bath. A grey deposit, which gave the proper chemical 
reactions of lead, was found upon the negative elec- 
trode ; but it was not possible to be certain that the 
lead had come from the patient's tissues, for it might 
liave been derived from lead compounds upon the sur- 
face of his body. 

The removal of metallic poisons from the body by 
electrolysis in the electric bath has not had much atten- 
tion since the time of Poey, who made a communication 
on the subject to the French Academy of Sciences in 
1855."' In this it is stated that mercury in metallic 
globules had been deposited upon the negative pole of 
the bath in which a person was placed after a course of 
mercurial inunctions. Here again it is most likely that 
the mercury, which seems to have been properly iden- 
tified by chemical tests, must have come from the 
surface of the skin of the patient. 

Althaus refers to a case of argyrism in which a large 
number of baths were tried with the object of removing 
the silver deposited in the patient's skin without the 
least success. Mercurial tremors are not often met 
with, but I have notes of one very well marked case in 

* Becquerel, " Traite des applications d'electricite a la therapeu- 
tique." Paris, 1857. 



which a rapid cure followed a course of treatment by 
sinusoidal baths. 

171. Rickets. — Children with rickets quickly respond 
to the electric bath. It is surprising to see how quickly 
they begin to improve in general health, and in their 
powers of standing and walking, and to see them gain 
in weight under the stimulating effect of the treatment. 
I have observed rapid improvement in several severe 
cases which were sent over to the electrical depart- 
ment at St. Bartholomew's, because their inability to 
walk had led to the belief that infantile paralysis 
existed. In Italy, Dr. Sagretti and Dr. Tederchi have 
reported a number of cases of rickets cured quickly and 
completely by electric bath treatment. 

172. Anaemia and chlorosis. — The electric bath is 
not often resorted to for the treatment of these con- 
ditions, because good results can generally be obtained 
by simpler means. In obstinate cases where ferruginous 
and tonic treatment does not answer satisfactorily, the 
electric bath should be tried. By its use the metabolic 
processes of the patient can be so efficiently stimulated 
that increased appetite and vigour can be secured for 
the patient, with improved colour, and a marked gain 
in weight. Under these conditions the catamenia will 
be re-established in a proper manner. I have several 
times had these patients under treatment by electric 
baths when they were not doing well under iron, and 
have found that the results of general electrification are 
distinctly valuable. Both in rickets and in chlorosis we 
have to do with simple forms of defective nutrition in 
which a simple electrical stimulation suffices to bring 
about a cure. 

173. Mental diseases. — The abundant evidence 
which we possess of the value of general electrification 


in the simpler forms of nutritional failure seems to point 
to the importance of applying the same kind of treat- 
ment in certain forms of insanity or mental failure. As 
a rule cases of this kind are not often met with in 
general practice, nor among the out-patients of general 
hospitals, and it will rather be in asylum practice that 
opportunities for trying electrical treatment will arise. 
A considerable amount of evidence has already accumu- 
lated to show that something may be done in this way. 
A valuable summary of the position up to about 1885 
will be found in Erb's work on Electro-therapeutics,'-'' 
together with numerous references to the writings which 
should be consulted in connection with the subject. 
Two cases which have come under my own experience 
may be mentioned here. One was that of a man 
referred to me by Dr. Gee with a note saying that the 
patient showed many of the signs of progressive 
dementia, but that as his symptoms dated from a recent 
attack of -influenza he might receive benefit from elec- 
tricity. The patient recovered rapidly from a short 
course of sinusoidal bath treatment, he regained his 
memory which he had completely lost, and was able to 
go back to his work. The other patient was a short- 
hand writer who had broken down in health completely. 
He was strange in his manner and sat huddled up in 
a dejected attitude. His wife said he was much 
changed in temper, and told me that on one occasion 
he had been found wandering about and had been 
brought home by a policeman. When he came he was 
treated by sinusoidal baths twice a week. A gradual 
improvement began and all his symptoms slowly left 
him. After three months he was able to begin work 

* Von Ziemssen's " Handbook of General Therapeutics," vol. vi. 
Smith, Elder & Co., 1887. 


again, and has continued well for more than a year. 
Dr. Robert Jones of Claybury Asylum tells me that he 
has been using induction coil baths in the treatment of 
some of his patients for two years or more and iinds 
that they are of decided value. 

He has kindly sent me the following communication 
on the subject : — 

" I have tried the electric baths in the case of 
adolescents mostly. In these and others the form of 
insanity was that of melancholia, some of the cases 
presenting well marked melancholia attonita (or anergic 

" These cases are marked by a gradual deterioration 
as a rule ; they stand or sit about in a fixed or passive 
attitude and have almost always to be considerably 
coaxed (if not forcibly fed) in order to get them to take 
nourishment. The mental condition is so unsatisfactory 
that some persons call the disease prmiary dementia 
and it is certainly not a very curable form. 

" After my conversation with you and my encourage- 
ment by your method of bath treatment I tried it upon 
eighteen males and five females. The record of weight 
in the case of the females was not kept ; of the five 
cases all improved greatly in health, but two were 
phthisical, and whilst undergoing bath treatment both 
gained several stones in weight. One died of phthisis, 
one was discharged recovered ; one has developed epi- 
lepsy, and one has recovered sufficiently to lead a useful 
life as a helper in the asylum. 

" Of the eighteen men, nine have left the asylum (six 
recovered, two relieved, and one improved but not 
recovered). All the men gained weight under treat- 
ment (they were weighed weekly and the record has 
been kept), the average gain of the nine who left the 


asylum being seven pounds during the bath treatment, 
which lasts for an average period of about seven weeks, 
but many received baths during nine or eleven weeks. 
The greatest gain of one case whilst under treatment 
was twenty-two pounds, the next nineteen pounds. 
Of the nine cases remaining under treatment, one is 
phthisical, one is suffering from progressive muscular 
atrophy; the others are considerably improved mentally, 
the stupor or profound melancholia having quite passed 
off, but they have not been well enough to be dis- 
charged from the asylum. I consider the results to be 
satisfactory. So little has yet been done in regard to 
the systematic treatment of the different forms of 
insanity by electricity that it is perhaps premature to 
form definite conclusions, but I consider that in electric 
baths we have an excellent and valuable stimulant to 
metabolism. The skin in the insane is in an abnormal 
condition, but whether the improvement after baths is 
due to the bath or this with electricity I am not pre- 
pared to say. 

" I should especially recommend electric baths in 
melancholia in adolescents and apathetic cases such as 
I have referred to. Certain puerperal cases of melan- 
cholia have also done well under treatment." 

174. Disorders of circulation— Raynaud^ s dis- 
ease — chilblains. — The electric bath is useful in cases 
of defective circulation, as in Raynaud's disease, chil- 
blains, and in cases of dead white pallor of the extremi- 
ties. Both the continuous and the interrupted current 
have been employed with good effect. One of the first 
signs of improvement in the numerous cases of infantile 
paralysis which have been under my care, is that the 
circulation in the paralysed parts is improved, the limb 
becomes warmer, and the chilblains disappear. Either 


a general bath or an arm- or foot-bath can be 

Dr. Barlow in his appendix to the translation of 
Raynaud's " Essays on Local Asphyxia,"'-"' recommends 
the constant current monopolar arm-bath, in the follow- 
ing words : — " The use of the constant current as 
recommended by Raynaud, has been adopted with 
advantage by several observers in cases of local 
asphyxia. The method which has been found most 
satisfactory by the translator, in four separate cases, 
has been the following : — Immerse the extremity of the 
limb which is the subject of local asphyxia in a large 
basin containing salt and water; place one pole of a 
constant current battery on the upper part of the limb 
and the other in the basin, thus converting the salt and 
water into an electrode Employ as many elements as 
the patient can comfortably bear, make and break at 
frequent intervals so as to get repeated moderate con- 
tractions of the limb. In a typical paroxysmal case, if 
the two limbs are similarly affected, it will be found 
that the limb which is subjected to the above treatment 
will more rapidly recover than the one which is simply 
kept warm." 

For chilblains the arm-bath or foot-bath with induc- 
tion coil is the most convenient domestic remedy, and 
succeeds in all but the most severe cases. I have used 
this mode of treatment in a number of cases and have 
repeatedly seen the prompt disappearance of chilblains 
follow its use. Moreover patients have several times 
informed me that after the cure of their chilblains by 
a course of coil baths they have found themselves with 
more resisting power afterwards, so that a course of 
baths at the beginning of winter has been sufficient to 
* New Sydenham Society, " Selected Monographs." 


get them through the whole of the cold weather without 
any return of the chilblains afterwards. The effect of 
the treatment therefore is more or less lasting. In the 
most severe cases of chilblains the constant current 
bath must be used. Its effects upon the circulation 
seem to be more intense than those of the coil, and after 
a constant current bath warmth and redness of the skin 
is greater than it is after a coil bath. 

Patients who know by experience that they are likely 
to have severe " broken " chilblains should not delay 
too long before beginning with the treatment, as the 
current acts very painfully upon any raw ulcerated 
surfaces. If these already exist they must be covered 
with a strip of oiled lint during the bath. 



Electrical Treatment in Diseases of the Brain: 
AND THE General Neuroses. 

Cerebral disease. Hemiplegia. Epilepsy. Chorea. Hysteria. 
Hypochondriasis and neurasthenia. Insomnia. Tremors and 
spasm. Writer's cramp. Tetany. Exophthalmic goitre- 
Migraine and headache. Mental diseases. 

175. — Cerebral disease. — Although to a great ex- 
tent it has been customary in treating cases of disease 
of the central nervous system to apply treatment to the 
peripheral parts only, nevertheless the seat of the lesion 
producing the paralysis or other symptom ought also ta 
be brought under the influence of the current if it can 
be accomplished without risk. 

Coil currents are not suitable for applications to the 
brain. In the first place the skin of the head is rather 
sensitive, and intolerant of all but very mild induction 
currents, and in the second it is not the simple stimula- 
tion of the brain which seems to be indicated so much 
as the "alterative" effects, and vaso-motor effects which 
may be set up by the battery current. 

It has been said that induction currents do not pene- 
trate the skull, and that this is the reason why applica- 
tions of these currents do not give the usual evidence of 
stimulation of the motor cortex. This belief, however, 
is absurd, on physical grounds, and it has been proved 
experimentally that currents applied to the head do 
traverse the brain, and if continuous currents have been 


proved to do so, nothing on earth could prevent alter- 
nating currents from doing so. 

Owing to the rounded shape of the head the con- 
ditions favour diffusion of current, and therefore the 
density of current (§§34 and 112) is greatly lowered as 
soon as the parts inside the skin are reached. The 
induction current though felt strongly at the point of 
contact of the electrode, is diffused away almost to 
nothing by the time it has reached the brain. On this 
account the battery current is the most suitable for 
treating the brain. 

The effects perceived when battery currents are 
caused to pass through the head, are peculiarly un- 
pleasant at the moment of make and of break, and 
as a general rule sudden makes and breaks are to be 
avoided as much as possible in applications to the head. 
The patient should be warned beforehand of the sensa- 
tions he will experience, and when opening or closing 
shocksare necessary, it is as well to give the patient a 
signal that he may know^ when to expect each. The 
sensation of a flash of light produced by stimulation of 
the optic nerves seems to be peculiarly alarming to 
some patients, probably because they connect it with 
their previous experiences of lightning flashes. Though 
we must not forget Duchenne's accident when treating 
the brain (see § 121), we may reasonably hope not to 
meet with a similar disaster in our own experience. 

A certain amount of work has been done on the 
electrical treatment of aflections of the brain, although 
in this, as in many other branches of electrical treat- 
ment, English medical men have contributed little. 
Much more, however, requires to be done before the 
modes of application and the results produced can be 
firmly established. 


The objects to be hoped for from appHcations to the 
skull in cerebral disease are as follows : — to promote 
the absorption of extravasated blood, to assist the cir- 
culation through the brain, to remove congestion, and 
to improve nutrition. All these may be classified as 
vascular effects, and a certain amount of evidence, 
partly experimental and partly clinical, has been col- 
lected, which seems to show that definite effects can 
be set up within the skull by electrical applications. 

Professor Leduc oi^3.ntes {Arch, d'electricite medicale, 
May, 1899) in a lecture on Cerebral Galvanisation re- 
lates the case of an elderly Judge who had been under 
his care at one time for facial paralysis. He was 
treated with the battery current and soon recovered 
from his paralysis, but afterwards continued to come at 
intervals for more treatment because of the comfortable 
feeling of increased mental vigour w^hich the galvanisa- 
tion of his head and neck afforded him. His w^ords are 
so striking as to deserve quotation. He said, " I feel 
lighter, and my ideas are more clear. I can concen- 
trate my attention more closely upon my work, I 
struggle more successfully against the sleep-producing 
effect of long pleadings. I grasp more clearly the argu- 
ments w^hich are advanced before me, and I can weigh 
them more exactly ; in fact, I find my intelligence is 
brighter and my work is more easy to do, and for that 
reason I come to you for an electrical application when- 
ever I am confronted by a fatiguing or difficult piece of 
work." A patient of my own, who had been receiving 
electrical treatment for nerve-deafness, though not very 
greatly improved so far as her hearing was concerned 
was so conscious of the good effect produced upon her 
general condition as to be most anxious that her 
husband should also be treated in the same way ! 


Prof. Leduc concludes his lecture with the following 
statements : — 

1. The brain is quite accessible by the battery- 

2. Applications to the brain are free from danger, 
and if carefully applied are free from discomfort. 

3. Negative applications appear to excite the func- 
tions of the brain, while positive seem to have a calming 
and depressing action. 

4. There is reason to hope for good effects in many 
diseases of the brain. 

5. Negative applications afford a means, probably 
the best means, of relieving the effects of mental over- 
work, and of raising the intellectual powers to their 
highest level. 

176. Hemiplegia. — In the less severe cases of hemi- 
plegia good results are commonly obtained by electrical 
stimulation of the affected limbs, and this is a very 
valuable fact, because so little can be done in other 
ways to improve the condition of old hemiplegic pa- 
tients. I have seen great benefit produced by the 
electrical treatment of such cases, and that not once 
or twice only, but frequently. In hospital practice the 
difficulty with old hemiplegic cases is rather to know 
when treatment may be discontinued, for as a rule the 
patients seem to wish to continue attendance inde- 
finitely. Improvement up to a certain point is the 
rule. After that continued treatment does very little. 
Much cannot be expected when there is well marked 
late rigidity. The series of cases recorded by Prof. 
Erb''^ seems to show that after an attack of hemiplegia 
the muscles may be left in a crippled condition from a 
sort of torpor of some part of the motor tracts, so that 
they remain for a time beyond the control of the will^ 
* " Electro-therapeutics." 


although there may be no absolute interruption in the 
conducting paths. Thus a patient may at once recover 
much of his lost power after a single vigorous electrifi- 
cation of his affected limbs. It is therefore very im- 
portant that this treatment should always be tried in 
cases where a patient is recovering imperfectly from 
hemiplegia. Treatment should not be commenced until 
four or five weeks after the attack, in order to avoid all 
danger of setting up fresh changes in the brain, and it 
may be repeated three or four times a week. A certain 
number of patients will be distinctly improved thereby. 
Most of the improvement likely to be obtained in this 
way may be expected to show itself in the course of the 
first month. It is also advised by Erb and others that 
further treatment may be directed to the seat of the 
lesion in the brain, the continuous current being em- 
ployed, the anode to the forehead and the sides of the 
head, and the kathode to the nape of the neck, the 
former electrode being slowly moved to and fro (labile) 
without interruptions ; this direction of the current has 
been chosen on account of its following the course of 
the motor tract. A current of one to five milliamperes 
is recommended, and the active electrode should be of 
medium size. This treatment is to be carried out daily 
for four weeks, the duration of each sitting being not 
more than five minutes. If aphasia is associated with 
the hemiplegia the anode may be applied to the region 
of the third left frontal convolution and island of Reil. 
I have no personal experience of the results of direct 
treatment of the brain in hemiplegia. As the morbid 
process in the brain is essentially a destructive one 
there must be limits to the amount of recovery which 
is possible. These limits will be determined by the 
extent and the situation of the damaged part. 


177. — Epilepsy. — This has been attacked by elec- 
trical methods, bat without any practical advantage. 
Arthuis states that he has seen good results follow from 
electrostatic treatment. 

Althaus gives three cases where treatment at once 
diminished the frequency of the attacks, and went so 
far towards effecting a cure that the intervals between 
the fits was prolonged from a few days to two months. 
Erb also reports that he has received a decidedly 
favourable impression from the treatment of epilepsy 
by the constant current. He advises that the anode 
be placed first on the side of the forehead, with the 
kathode to the nape of the neck, with a weak current 
for one minute, and secondly in the middle line of the 
head in front with the same current and for the same 
length of time, the kathode being over the occiput. 
The treatment of the seat of the aura as well is recom- 
mended by Althaus. 

178. Chorea. — Statical electricity has been success- 
fully tried in this disease. In 1849 Dr. Golding Bird" 
reported that out of thirty-seven cases thirty had been 
cured by electrical treatment, while five of the others 
were relieved. The plan of treatment was the applica- 
tion of sparks to the spine. The shocks from a Leyden 
jar were found to be decidedly harmful. 

The patient was insulated and connected with one 
of the conductors of the electrical machine. A ball- 
electrode with insulated handle was attached to the 
other conductor, and sparks were applied to the spinal 
column and the affected limb, until a papular eruption 
was produced. In the case of children the mother or 
nurse was insulated with the child in her arms, and 
sparks applied to the child's back and limbs as before. 
* " Lectures on Electricity and Galvanism," London, 1849. 


In the Guy's Hospital Reports in 1853, Sir William Gull 
reported twenty-five cases of chorea treated by statical 
electricity. Nineteen were cured and five improved ; 
only one resisted the treatment. He says : " The fact 
stands well established that electricity is at present to 
be ranked amongst the means at our disposal for the 
cure of chorea, and that in severe cases its effects are 
often truly surprising. Where other means cannot be 
employed; when the patient is scarcely able to swallow; 
where the skin is abraded from the prominent bones of 
the emaciated frame ; when the powers of life seem 
nearly exhausted, sparks of electricity drawn from the 
whole length of the spine wdll often, after a few repe- 
titions, effect a favourable change, and enable us to 
administer other means of cure." In spite of this em- 
phatic testimony the treatment is now-a-days quite 

In the United States Monell has reported recent 
successful cases. 

With modern machines the negative breeze to the 
spine would probably alarm the patient less and prove 
as efficacious (§ 102). 

In chorea electrical treatment should surely be tried, 
at least in cases which have lasted a long time, and 
resist the ordinary medical treatment by rest and drugs. 

It often happens that patients seem to recover imper- 
fectly from chorea, because certain habitual movements 
remain when the disease has otherwise disappeared. 
For these late symptoms electrical applications are very 
suitable, I have seen them quickly dispelled in several 
such cases by a course of electrostatic treatment with 
sparks. Indeed all those which I have been asked to 
treat for this condition have recovered within two or 
three weeks. 


Eecent severe chorea has never come under my care 
for electrical treatment. I am therefore unable to sup- 
port or deny the statements of Golding Bird and others, 
as quoted above. The general feeling on the matter 
seems to be that electrical treatment might do harm 
hy alarming the patients suffering from it. But the 
breeze discharge is not painful or alarming. 

The paretic states v^hich are often left after chorea 
may be treated by electricity with great advantage. 

179. Hysteria. — Hysterical affections have been 
very largely treated by electricity, and from the pecu- 
liar nature of the affection, good results have followed 
the most diverse forms of electrical treatment. The 
moral effect of the treatment, particularly when it is 
associated with sparks or with shocks, is suitable to the 
state of mind of hysteria, and therefore the literature of 
Medical Electricity, from the time of John Wesley's 
"Desideratum " onwards, is full of more or less wonder- 
ful cures of such cases by electricity. At the same time 
the value of electrical treatment lies rather in the direc- 
tion of dispelling symptoms than of curing the morbid 
state, and it is necessary to be prepared for occasional 
difficulties and disappointments, even in hysterical 
cases, although good results will often be obtained. 
We must also be careful not to claim too much for the 
electrical part of the treatment when it is successful, 
for it may happen that the touch of an electrode will 
cure even when there is no current. Several cases of 
this kind have come to my notice. Strong galvanic 
shocks have been used for cutting short an hysterical 
fit, but the most useful role of electricity in hysteria is 
for the removal of paralysis, anaesthesise and spasms ; 
for these symptoms the induction coil is most usually 
employed, either with an ordinary electrode or with the 


dry metallic brush. Statical treatment, especially the 
treatment by sparks, is also valuable in these cases, 
and has been very largely practised. Hysterical 
aphonia can sometimes be dispelled by coil currents 
applied to the throat from outside, and for the most 
part this method is better than the more severe applica- 
tion of the electrode to the fauces, or to the larynx, 
because the patient will not always submit to the latter 
method. For the hysterical condition, as distinguished 
from the special symptoms, it is advisable to use 
general electrification, and especially the electric bath 
or statical charging and breeze treatment. 

The electrical treatment of hysteria does not consist 
merely in severe applications ; the treatment may be 
briskly applied, but pain must not be deliberately in- 
flicted. In the treatment of functional aphonia by 
sparks or shocks, there are cases w^here the patient 
becomes alarmed and screams out aloud and so be- 
comes cured. Others show the greatest equanimity and 
do not cry out, neither are they cured, or at best only 
after many visits. 

An important consideration is the diagnosis between 
hysteria and organic disease of some obscure kind. 
It is not at all uncommon for hysteria to be associated 
with serious disease, for instance with phthisis ; more- 
over, when the diagnosis has been based upon the 
alleged presence of a persistent localised pain in a 
female patient, it may after all turn out to be due to 
some serious latent mischief. I have known two cases 
where patients with early malignant disease of the 
vertebrae were supposed to be suffering from hysteria 
alone.* It is not wise to diagnose all sorts of condi- 

* Cf. Dr. Buzzard, Brain, 1890. " On the Simulation of Hysteria 
by Organic Disease of the Nervous System." 


tions as hysterical merely because they are not under- 

180. Hypochondriasis and neurasthenia. — In 

these conditions the methods of general electrical 
treatment are of great value, especially the electric 
bath, which answers very well to the indications for 
treatment required by these cases. Direct treatment 
to head and spine with the constant current (see § 175) 
should also be tried. The conditions which are now-a- 
days described under the general term neurasthenia, 
are conditions of general debility or of debility affecting 
chiefly the nervous system. Usually they depend upon 
a failure of nutrition, often started by some definite 
disturbing cause, such as mental worry or a severe 
illness ; the digestion becomes impaired, and this keeps 
up a state of defective nutrition until at last the patient 
falls into the more or less pitiable condition which is so 
well known. 

In other cases errors in diet, extending over a long 
time, may be the cause of the neurasthenia, and the 
patient himself may be quite unconscious of this. Fre- 
quently these patients will declare that they are most 
careful in their food, but if the medical man has oppor- 
tunities of observing them he will soon find out whether 
this is the case or not. Generally it is not so. Dys- 
pepsia is almost universally present, and should be 
carefully attended to. The difficulty of curing neuras- 
thenics by a few bottles of medicine also tends to make 
the medical man grow impatient ; but indeed it is 
unreasonable on his part to expect a cure in that way. 
The only proper way of treating neurasthenics is by 
enforcing a proper diet and proper rules of life, and by 
insisting on adequate and refreshing exercise, assisted 
by some method of general stimulation, and it is in this 



capacity that general electrification serves as a useful 
aid. Many people tend to become neurasthenic in the 
slighter degrees when their daily cares exceed a certain 
point, and when business matters or other troubles 
begin to spoil the appetite, and to interfere with proper 
exercise and a due amount of sleep, then troubles of the 
neurasthenic sort are likely to begin. 

I have had opportunities of seeing the effect of general 
electrification upon a number of these cases, and I am 
satisfied that vigorous stimulation by the electric bath 
and induction coil or sinusoidal current, carried out two 
or three times a week, has far more effect upon neuras- 
thenics than any other mode of treatment. Of course 
it should be used in conjunction with proper rules for 
diet and regimen, and the original depressing cause of 
the disease should be found, and if possible, eliminated. 
If this cannot be done no treatment will be of much use. 
For instance, where domestic unhappiness or discontent 
is a factor, one may treat in vain. 

181. Insomnia. — General electrification frequently 
produces a tendency to sleepiness in patients. The 
sinusoidal or coil bath has an especially strong effect in 
predisposing to sleep. So has the static charge (posi- 
tive) with head breeze. This application may be given 
for half-an-hour or longer. Armstrong has found cen- 
tral galvanisation very useful (§ 153). 

182. Tremors and spasm. — The various kinds of 
tonic and clonic spasm, and of tremors, come not un- 
commonly for electrical treatment because many of 
them are so difficult to relieve by any other known 
method. The results vary very much, as might be 
expected in a group of affections whose nature is very 
imperfectly understood, and which may arise from 
many different causes. 


The tremors of paralysis agitans probably signify a 
senile or some similar failure of the motor cortex, and 
are not likely to be cured by electricity. The tremors 
of metallic poisoning are not so commonly met with as 
to be likely to come under electrical treatment very 
often. The electric bath, with sinusoidal current, 
quickly cured the only case of mercurial tremor which 
has come under my notice (see § 170). 

In cases of tremor of the arm and hand, and of the 
leg after local injury, and in cases of spasm and con- 
traction of fingers after sprains of the wrist, seven cases 
in all, five were relieved by electrical treatment ; some 
by means of electrostatic sparks, others by the use of 
the constant current, with the anode to the affected 

Tremors, and spasms affecting hemiplegic limbs, are 
not favourable cases. In a case of tremors of this kind 
in a child of eleven, in whom partial hemiplegia came 
on during typhoid fever, the electrical treatment of the 
brain, for a long time carefully tried, has yielded no 
result. So with spasm in hemiplegics, electrical treat- 
ment even for long periods of time is of little use. 

Hysterical tremors and spasms are also common, and 
they do not invariably yield to electricity, though a 
good result may be expected in about half the cases. 
For them the electrostatic methods are the best. Two 
out of three cases of facial spasm were definitely 
arrested by electrical treatment, both were in women, 
aged 44 and 47 respectively. In a third patient, a man 
aged 30, who had suffered for three years, the treatment 
was of no use. Applications of the anode, stabile, are 

Wry-neck, from contraction of the sterno-mastoid, 
has been relieved in less than half the cases. . 


It must not be forgotten that spasmodic affections are 
not infrequently reflex phenomena, thus there may be 
severe spasm of the muscles of mastication from inflam- 
mation about the gums or throat, and inflamed cervical 
glands sometimes cause wry neck. Or there may be 
spasm from direct irritation of the nerves as in wry 
neck from disease of the cervical vertebrae. Before 
commencing electrical treatment a careful examination 
should be made for any source of irritation, and this, if 
possible, must be remedied. 

In children, and also, though less commonly, in 
adults, wry neck may be due to exposure to cold or 
wet, and this form has been called " rheumatic," and 
yields easily to simple measures. Muscular spasms are 
also common in hysterical and emotional people, and in 
such they may come on quite spontaneously or as a 
sequel of some slight injury or illness. Apart from 
hysteria we often find that various forms of spasm, and 
especially wry neck, have been brought on by prolonged 
mental anxiety. 

Facial spasm is not uncommon in its slighter degrees, 
in the form of twitchings of some of the facial muscles. 
Sometimes the twitchings are very frequent and severe, 
and though at first they can be controlled by an efl"ort, 
they may in time become quite uncontrollable. The 
commonest form of spasm, however, is wry neck, tonic 
or clonic. The sterno-mastoid is usually at fault, but 
occasionally the wry neck is produced by contraction of 
the splenius capitis or the trapezius. 

Very often no cause can be found for the wry neck, 
and perhaps it is most obstinate in these very cases. 
Electrical treatment has been often tried for spasmodic 
affections, and it is very successful in some, but fails 
completely in most. In hysterical cases, the dry brush 


or electrostatic sparks may always be tried with good 
prospects of improvement. In the other cases the 
battery current is better, the stabile action of the anode 
being employed with currents of lo to 20 milliamperes 
over the affected muscles and its nerves. Erb has 
recorded twenty cases of spasm in various muscles, 
almost all of which were cured by electrical treatment ; 
a few of them improved only after a very large number 
of sittings, but others were very promptly cured by 
three or four. 

183. Writer^s cramp. — This is the best known form 
of a series of spasmodic affections which are produced 
by prolonged over-work of certain muscles, particularly 
when the work done is of a complicated and highly 
co-ordinated kind. The name of function spasm or 
occupation spasm has been given to this group. Be- 
sides those whose occupation is writing, violinists, 
piano-players, tailors and shoemakers, are subject to 
similar attacks in the muscles which they use most 
often. In writer's cramp there is a combination of 
muscular weakness, tremor, pain, and spasm ; either of 
these may predominate, the first and chief seat of the 
cramp or palsy is in the intrinsic muscles of the thumb 
and in the first dorsal interosseous ; if the occupation be 
persevered with, other muscles are called in to take the 
place of those which are deranged, and soon they also 

The characteristic feature of these affections is that 
the weakness, or pain, or spasm, is produced only by 
one particular kind of work. The hand of a man with 
writer's cramp remains quite useful to him for every- 
thing except for writing, and so with the other forms of 
true occupation spasm. 

It is only in advanced cases that the symptoms are 


provoked by other uses of the same muscles. When 
symptoms resembUng those of writer's cramp are pro- 
duced by any sort of movement involving the use of the 
affected muscles, some other explanation of them should 
be carefully looked for, as the case may turn out not to 
be a true case of writer's cramp. 

I have notes of twenty-six cases of writer's cramp, 
four occurring in women. Pain, tremor, and numbness, 
are the symptoms most commonly complained of. 
Spasm is only noted in eight. The hand and forearm 
are the usual seat, though in one the symptoms con- 
sisted of pains confined to the shoulder, and weakness 
and slowness in writing. One patient gave up writing 
and became a maker of foot rules, but after tw^o years 
of this carpenter's work he found similar symptoms 
returning to the muscles most employed. Another 
patient, a woman, gave up writing and became a nurse, 
but a year and a half later she returned, for being out 
of employment she began writing again, and the writer's 
cramp returned. Thirteen cases are reported as 

Of other forms of occupation spasm I have notes of 
fifteen cases, four in women, their occupations are very 
varied, but in all there was a severe strain upon some 
muscles of the hand ; eight are reported cured ; in one, 
a violinist, the spasm affected the ring and little fingers; 
in a pianist it was the left hand which failed. 

Electricity is of value in this disease, but it must be 
helped by the complete abandonment for a time of the 
habit which has caused the development of the disease. 
The constant current, without sudden breaks, is to be 
used ; currents of ten to fifteen milliamperes if the 
patient can bear it. The skin and the electrodes to 
be thoroughly moistened with warm water. Different 


writers prefer different positions for anode and kathode, 
thus Dr. Poore'-*"' places the anode in the axilla, and the 
kathode over the ulnar nerve just where it leaves the 
biceps on its way to the olecranon. The patient is 
also made to exercise the interossei by separating and 
approximating the fingers rhythmically. i\nother plan 
recommended by the same writer is to place the anode 
over the median nerve at the inner border of the biceps, 
and the kathode over the body of the flexor longus 
pollicis, while the patient is made to flex rhythmically 
the distal phalanx of his thumb. Other similar plans, 
including the combination of a descending current, with 
rhythmic exercises, may be used. 

Max Weissf in discussing the electrical treatment 
of writer's cramp, points out that three conditions may 
be found in these cases. (i) Spasms ; (2) tremors ; 
(3) paralyses ; and sometimes combinations of these 
morbid states. In the spasmodic cases which are 
usually tonic rather than clonic, on taking up the pen, 
the thumb, index and middle fingers, and especially 
the thumb and index, pass into a state of tonic spasm. 
He considers that the disturbances are situated in the 
median and ulnar nerves, not in the motor cortex nor in 
spinal cord. The treatment he recommends is the use 
of constant currents of from two to five or eight milli- 
amperes, for fifteen to twenty-five minutes, with abso- 
lute rest from writing ; applications twice daily during 
the first weeks, afterwards diminishing to two or three 
times a week. Anode in the palm if extension is the 
main symptom, on the dorsum if flexion. Kathode to 
be placed on the nape of the neck, or on the upper and 

* " Electricity in Medicine and Surgery," 1876. Medico-Chirnr- 
^ical Transactions, 1887. 

t Centralblatt fur die gesamm. Therap., April, i8gi. 


inner part of the arm. Anode may also be applied to 
the tender points for ten to twenty minutes. 

Generally speaking, the anode should be employed 
at the seat of the symptoms, the kathode being placed 
centrally, over the first part of brachial plexus, or on 
the upper dorsal spine. 

Dr. Poore's preference for a descending direction of 
current, is probably due to the intention of setting up 
the " refreshing " effect upon the nerves and muscles of 
the limb (§ 125). 

In Dr. Poore's later article on writer's cramp he has 
shown that a certain number of the cases have signs 
of some slight central lesion, either in brain or cord. 
There may be altered irritability in the affected muscles, 
and tenderness of the nerve trunks. It is possible 
that some neuritis may be present in some of these 

Monell has advised static treatment for writer's camp 
and claims to be able to cure the condition without any 
interference with the occupation of the patient. 

184. Tetany. — This form of spasm, although not 
very common, deserves mention here, because of the 
peculiar increase in electrical irritability which forms 
one of its leading symptoms. There is also, as is well 
known, an increased irritability of the nerves and 
muscles to mechanical stimulation, and this is not 
confined to any particular nerve, although it has been 
most commonly observed in the facial nerve (facial 
irritability). The peculiar spasms can be evoked by 
compression of a nerve trunk or of the main artery of a 
limb, or by a rough touch over a motor nerve. Erb** 
first showed that the electrical irritability was also in- 
creased in this disease. 

* Arch. f. psychiatric, 1874. 



In a recent paper Dr. Bernhardt** has reported three 
cases in which the electrical reactions were examined, 
his results compared with the normal irritability of the 
same nerves are represented in the following table, 
which gives the current in milliamperes required to 
produce the first KCC contractions. 



Tetany. 3 Cases. 

Facial .... 

o-g — 3 milliamperes 

0-5 — 1-5 milliamperes 

Median .... 

o-g— 3-3 


Musculo-spiral . 

2 —5 

0-25 — i-o ,, 

Peroneal . . . 

I — 2 ,, 

0-5 — i-i 

ACC and KDT (kathodal duration tetanus) were also 
more easily produced than usual. In the electrical 
treatment of tetany the influence of the anode stabile 
is to be directed to the affected parts, and the current 
must be gradually diminished at the termination of the 
sitting to avoid the ill effect of sudden anodal opening. 
The results of treatment are said to be entirely favour- 
able, but the disease is one which tends to disappear 

185. Exophthalmic goitre. — Quite a large litera- 
ture has grown up on the electrical treatment of this 
disease. Many favourable cases have been reported 
with various kinds of electrical treatment. So long 
as the pathology of the disease remains uncertain, the 
electrical treatment must continue to be tentative. It is 
by no means successful in all cases, although numerous 
cures have been reported in the journals. 

* Berlin Klin. Wochenschrift, June, 1891, No. 26. 


It has been assumed that the seat of the disease is in 
the vaso-motor system, and especially in the cervical 
sympathetic. It is important to bear in mind, as has 
been pointed out by Gowers, that the sympathetic sys- 
tem is represented in the brain, and on this account 
the treatment should not be confined too strictly to the 
region of the neck. 

In this country Cardew reported'" a short series of 
cases where the constant current produced great im- 
provement in the symptoms. In nearly all of them the 
frequency of the pulse-rate was reduced, the enlarge- 
ment of the thyroid was diminished, and the nervous 
condition of the patient was improved.- He suggested 
that the treatment should be carried out by the patients 
themselves three times a day, and also at other times if 
the palpitation of the heart should become severe. He 
advised that a current of two to three milliamperes 
should be applied for six minutes ; the anode to the 
region of the lower cervical spine, the kathode to the 
side of the neck, labile, from the mastoid process to the 
clavicle. The two sides of the neck should be treated 
alternately, and the patient should persevere with the 
treatment for two months at least. He also declared 
that the diminished resistance of the body, which has 
been observed in this disease, is due simply to the in- 
creased perspiration and moisture of the skin, and this 
opinion is now generally accepted. 

Owing to this lowering of resistance a small electro- 
motive force is sufficient to give the required strength 
of current. The number of cells in circuit must there- 
fore be small, commencing with as few as three or four, 
and the galvanometer readings must be carefully at- 
tended to. 

* Lancft, July, i8gi. 


General stimulation by means of the electric bath can 
also be tried. In my own experience I have never seen 
a cure of Graves' disease by electricity. 

186. Migraine and headache. — The results of 
treating migraine electrically are sometimes encourag- 
ing, and at others quite disappointing. 

In severe and typical migraine there is not much 
use in trying to dispel an attack by electricity. In the 
slighter forms of one-sided headache, the pain may be 
immediately and permanently relieved by treatment 
with the constant current, the anode being applied to 
the seat of pain ; the headaches of constipation are not 
usually improved in this way. 

The electric breeze to the scalp has a very agreeable 
effect in headache, and the relief it affords is sometimes 
permanent, though at others it is only temporary. Cases 
have been reported in which a prolonged course of elec- 
trostatic charging has been followed by the disappear- 
ance of the tendency to attacks of migraine. 

187. Mental diseases. — Some work has been done 
in the treatment of the insane by electricity, chiefly by 
means of the application of the battery current to the 
head. It is also certain that general electrification by 
the sinusoidal or coil bath is very useful in many of 
the slighter cases of melancholia, by improving the 
metabolic activity of the tissues. See also § 173 for 
a valuable report of the results of treatment by the 
coil and bath in cases of this kind. 



The Spinal Cord and Nerves. 

The spinal cord. Treatment of paralysis. Infantile paralysis. Pro- 
gressive muscular atrophy. Injuries of nerves. Special nerve 
injuries. Neuritis. Neuralgia. Sciatica. Anesthesia. Nerves 
of special senses. 

1 88. The spinal cord. — Treatment may be directly 
applied to the spinal cord by means of electrodes placed 
upon the back over the vertebral column. In this way 
currents can be made to traverse the spine in a longitu- 
dinal direction. When the effect is to be localised at 
one particular level the indifferent electrode should be 
large and placed on the front aspect of the trunk, while 
the other is applied to the back at the position required. 
Direct treatment of the cord has been carried out for 
the relief of certain chronic disorders, and favourable 
cases have been reported by Erb and others in locomotor 
ataxy, in concussion and other injuries of the spine, 
in progressive muscular atrophy, lateral sclerosis, and 
chronic myelitis. 

The systematic electrical treatment of diseases of the 
cord requires very much more study before it is likely 
to be accepted by the medical profession as a treatment 
of real value. In spite of the fact that a certain number 
of successful cases have been reported, the effect of 
electrical treatment upon these spinal cord diseases is 
usually negative. In acute myelitis electrical treatment 
should be avoided as it is likely to do harm. 


The results of treating locomotor ataxy and progres- 
sive muscular atrophy have hitherto for the most part 
been negative ; where locomotor ataxy has been said to 
have been improved or cured, the diagnosis may have 
been erroneous, and the symptoms may have been due 
to neuritis. See also § 191 and § 192 for further 
details. It is important to distinguish between the 
statement that the results of treatment are negative, 
and the quite different statement that electrical treat- 
ment is useless in these complaints. It is just possible 
that further study may justify the belief of certain good 
observers that something may be done by electricity to 
arrest the progress of these chronic spinal cord diseases. 

189. Treatment of paralysis. — Certain funda- 
mental principles of treatment apply to nearly all cases 
of paralysis. If possible there should be treatment of 
the seat of disease, brain, cord, or nerves, as the case 
may be, and also treatment of the paralysed muscles. 
The seat of disease is to be treated in the hope of set- 
ting up trophic or vasomotor changes there, in order to 
remove the cause of the paralysis, if it be possible to do 
so, and the muscles are to be treated in order to main- 
tain and stimulate their nutrition. Stimulation of the 
peripheral parts also acts usefully by influencing the 
central organs through the medium of the sensory 
nerves, and in a reflex manner may set up motor im- 
pulses along the nerves to the paralysed parts. When 
the paralysis is purely motor, and the sensory functions 
of the affected parts are normal, this reflex mode of 
stimulation is of importance, and it follows that peri- 
pheral excitation of a limb in infantile paralysis, or of 
the face in Bell's palsy, is a rational procedure. 

When a nerve trunk has been injured and repair is 
taking place, it is often noticed that voluntary power 


returns before the return of electrical reactions in the 
nerve and muscle. Here direct treatment of the nerve 
trunk, by applying the electrodes to it above the seat 
of injury, or indirect treatment through the agency of 
reflex stimulation of its centre may prove useful. Erb 
saj^s : — "A hindrance in the motor conduction, which 
cannot be overcome by the will, may perhaps be con- 
quered by a stronger artificial stimulation, and the way 
thus made clear for voluntary excitation. Hence, if we 
allow the electric irritation to act energetically above 
the seat of lesion, the hindrance may perhaps be in this 
way removed." 

When the battery current is used the paralysed 
muscles are to be treated by applications of the kathode, 
which must be well moistened and moved slowly 
and firmly over the affected muscles ; the current to be 
between five and ten milliamperes, and the duration 
of treatment ten minutes. It is important not to use 
electrodes which are too small. A two inch size (five 
centimetres) is suitable, and less painful than smaller 
sizes, because the density of the current at its surface is 
less. If five milliamperes should seem to be painful in 
the case of a child the current must be reduced ; when 
the skin is well wetted the painful effect of the current 
is diminished. In addition to the labile applications the 
current may be opened and closed or even reversed 
suddenly from time to time, for the sake of exciting 
contractions in the paralysed muscles. The indifferent 
electrode is to be placed over the spine in the neigh- 
bourhood of the central lesion. 

When the induction coil is used a similar method of 
application may be adopted, the current being carefully 
regulated so as not to produce discomfort. Or both 
poles may be applied to the affected part, one being 


buckled round the limb in a position close to the nerve 
trunk, while the other is manipulated over the muscles, 
•or lastly, both electrodes can be applied direct to the 
muscle. If the muscles do not respond to the coil it 
has been customary to use the battery current, although 
in such cases the induction coil may give results which 
are quite as good, or better. It must be remembered 
that the difference between the induction coil current 
and the battery current applied in a labile manner is 
only a difference in degree, one giving frequent and 
sudden variations of current, and the other infrequent 
and gradual variations. I have seen large numbers of 
cases with the reaction of degeneration who recovered 
under treatment by means of the induction coil alone. 

The continually expressed opinion that for muscles 
showing the reaction of degeneration the induction coil 
is useless is a belief based more on theory than on 
practice. The every day experience of those who are 
occupied with electro-therapeutics is completely against 
it. The results obtained by Duchenne from induction 
coil currents are a sufficient testimony to the value 
of this mode of treatment in all kinds of paralytic 

It is true that a muscle showing the reaction of 
degeneration w411 contract to the constant current only, 
and in so far as the contraction of the muscle is a good 
thing for the muscle, the constant current may be better 
than that of the induction coil ; but it is absurd to think 
that the amount of benefit can be measured by the 
amount of contraction set up in the muscle. A muscle 
which is completely and permanently cut off from its 
nucleus of origin will continue to degenerate and waste, 
however persistently it be made to contract by treatment 
with the constant current. This matter of the relative 



advantages and virtues of constant and interrupted 
current dates from a long way back. Each has been 
warmly advocated by its partisans to the exclusion of 
the other since the days of Duchenne and of Remak. 

But in paralysis any form of electrical application is 
of value, chiefly, if not entirely, as a means of stimulat- 
ing the activity of the living tissues of the part under 
treatment ; with the constant current of a battery the 
stimulation is chiefly obtained when the current is made 
to vary whether by interruptions or reversals, or by 
movements of the electrode over the surface, while with 
the coil the variations are produced by the apparatus. 
So far as the action of electricity upon the growth of 
muscle is concerned, the experiments of Debedat''' are 
interesting, as they prove the superiority of the induc- 
tion coil for stimulating the growth of muscle. 

He reported the results of experiments made on the 
muscles of young rabbits with the various kinds of 
electric stimulation used in medical treatment. The 
experiments were made on the group of hamstring 
muscles ; those of the left side were stimulated in 
various ways daily during twenty days, for four min- 
utes a day ; those of the right side were left for purposes 
of comparison. At the end of the period the animals 
were killed, and the muscles of the two sides carefully 
removed and weighed ; portions were also hardened and 
examined microscopically. The modes of stimulation 
were as follows: — i. The induction coil current, lasting 
for one second, and followed by one second of interval, 
and so on for four minutes. 2. The battery current of 
two milliamperes, with the same periods of stimulation 
and repose. 3. Electro-static sparks two to three 
millimetres long, repeated every two seconds. 4. Tetan- 
* Arch, d'clectricite medicale, February and March, 1894. 


isation of muscles for four minutes by means of an 
induction coil, without any intervals of repose. 
5. Steady galvanic battery current for four minutes 
without intervals of repose. The results showed a gain 
of 40 per cent, in weight on the stimulated side with 
the rhythmic induction shocks, and of i8 per cent, with 
the rhythmic battery current. The effect of the static 
sparks was nil ; the prolonged tetanisation caused a loss 
of weight ; the prolonged steady battery current a 
slight increase in weight. Adhesions had been formed 
between the skin and the muscle at the points of appli- 
cation of the electrodes in this last. The gain in weight 
was due to a true growth of the muscle ; the loss was 
accompanied by histological evidence of damage to the 
muscle fibres. The author concludes that the most 
advantageous mode of promoting the growth of muscle 
by electricity is to use an induction coil, and to arrange 
the periods of contraction and repose of the muscle so 
as to approximate to the conditions of a muscle during 
the performance, of rhythmic gymnastic movements — 
namely, about thirty periods of contraction and thirty of 
rest per minute, prolonged tetanisation being distinctly 

These experiments are of great value as they indicate 
clearly the best method of carrying out treatment, when 
the nutrition of a muscle is the object desired. 

Whenever children are to be treated by electricity 
great care must be taken not to frighten them by sudden 
shocks, the current used must never be so strong as to 
alarm them or make them cry, and it is important 
that the apparatus should work very smoothly and 
evenly. Many coils are defective in the matter of 
contact breaker ; until lately there has been little atten- 
tion given to it, and any sort of vibrating spring has 

z 2 


been thought good enough, but there is a very great 
difference between a good and bad one. 

I go. Infantile paralysis. — There is no doubt that 
electrical treatment is of the utmost value in this dis- 
ease. The long lasting paralysis and atrophy which it 
so often leaves behind is apt to be discouraging, but 
once a regular system of electrical treatment has been 
instituted a gradual improvement soon becomes per- 
ceptible. As the result of an electrical testing which 
has shown seriously impaired reactions, many people 
have been told that their children were beyond reach of 
treatment, although it is quite certain that prolonged 
electrical treatment will do good to nearly all cases of 
infantile paralysis, particularly if not more than a year 
or two has been allowed to go by since the incidence of 
the disease. Even after that lapse of time much may 
still be done. 

There is a formula in which the prognosis of infantile 
paralysis has been commonly summed up. It is as 
follows : — If the ganglion cells supplying the muscle are 
destroyed recovery must be impossible, and if the cells 
are not destroyed treatment is unnecessary, because the 
patients will get well of their own accord. This for- 
mula, I am sure, has done a great deal of harm, for it is 
widely accepted because it saves such a lot of trouble. 
But it starts from the assumption that the disease must 
either destroy all the motor cells of a muscle or else 
must leave them all uninjured, and this assumption is 
certainly not correct. On the contrary, the damage to 
the motor cells may be of any degree of severity or of 
any extent, and the paralysis may vary between slight 
weakness and complete loss of all motor power. 

It is reasonable to suppose that a focus of disease in 
the anterior cornu of the cord may destroy some of the 


nerve cells of the nucleus of origin of a muscle, while 
others in the same nucleus may escape, and this might 
especially be the case if the nucleus of origin is an 
extensive one. On this point the statements of 
Sherrington are conclusive. In the Medico-Chiruvgical 
Transactions, vol. 82, p. 456, he writes : — " The position 
of the nerve cells sending motor fibres to any one 
skeletal muscle is a scattered one, extending throughout 
the whole length of the spinal segments innervating 
that muscle ; in the limb regions many muscles receive 
their motor fibres from as many as three consecutive 
spinal roots, and the bodies of the nerve cells inner- 
vating those must therefore, inside the cord, extend 
through the length of three whole segments of the cord 
as a continuous columnar group, and in each transverse 
level of the cord these cells must lie commingled with 
nerve cells innervating many other muscles. Hence no 
traumatic injury of the spinal cord can ever paralyse a 
single muscle alone and apart from others." 

This being so one can readily understand how a 
muscle may be partly crippled by poliomyelitis and yet 
may retain partial voluntary power through the sup- 
port of such of its ganglion cells as happen to survive. 
There is also the possibility of neighbouring cells taking 
up the work of those destroyed. The object of elec- 
trical treatment then is to stimulate and develop any 
surviving muscle fibres, and if possible to make them 
numerous enough and strong enough to form an useful 

Duchenne long ago pointed out that a muscle crippled 
by infantile paralysis may still contain a few living 
functional muscle fibres, and that these may easily be 
overlooked in an ordinary electrical examination of the 
muscle, but that they can be successfully cultivated by 


persevering treatment. There is no doubt that cases 
admitting of similar interpretation do occur, for ex- 
ample, I have seen a quite respectably sized mass of 
calf-muscle develop in a limb which for two years at 
least had shown no trace of electrical reaction of any 
sort in that region, and the same in other muscles, 
notably in a deltoid muscle which, after remaining for 
nearly three years completely atrophied as the remnant 
of an extensive paralysis of the upper arm, eventually 
began to grow, and to show faint contractions of normal 
quality to the induction coil. It is an interesting point 
that the new development of the calf just mentioned 
has taken place almost entirely in the outer head of the 
gastrocnemius. In another case in which the deltoid 
was paralysed, there now is good growth in its posterior 
third, and there only. 

If the surviving fibres can by cultivation be made 
numerous enough to have some useful voluntary power, 
they will be able to maintain themselves in a way 
which is impossible to them if they are unable to do 
any work. I have had an opportunity of testing and 
dissecting the muscles in an amputated leg the seat of 
severe infantile paralysis of old standing. The age of 
the patient was 20 years, and the limb had been dis- 
eased from childhood. The muscles of the leg were 
all extremely atrophied, degenerated and fatty ; in fact, 
the calf was almost like adipose tissue, but still con- 
tained a sufficient number of normal muscle fibres to 
show visible contractions to the induction coil current. 
The other muscles of the leg though in a state of 
advanced atrophy, all contained fibres which were able 
to respond either to the induction coil or to the battery 
■current. The intrinsic muscles of the foot were normal. 
These reactions showed, to my mind, that even at that 


time there must have been some surviving gangUon 
cells in the affected portion of the cord, and that a 
certain degree of trophic nervous influence was still 
available for the muscles of the paralysed limb. 

The persistence for several years of even a reaction 
of degeneration implies, I believe, that the muscles 
showing it are not wholly cut off from their spinal 
■centre. When there is complete division of a nerve 
trunk, the muscles cease to react at all to electricity in 
a year or less, but in infantile paralysis a well marked 
reaction of degeneration may be demonstrated ten or 
twelve years or more after the original attack ; here 
then, clearly is a distinction between the condition of a 
muscle cut off completely from its nucleus of origin by 
section of its nerve, and a muscle paralysed and wasted 
by severe poliomyelitis. 

Again a muscle which has been for a time without 
any kind of reaction may develop a reaction of de- 
generation at the time of its commencing recovery. 
This may occur after the reunion of a divided nerve, 
(see § 193 for a case) or in poliomyelitis; and it seems 
to suggest that there may be " trophic cells " as dis- 
tinguished from purely motor cells and that in infantile 
paralysis the trophic cells may not always suffer in the 
same degree as the motor cells, and that fibres from the 
trophic cells may have a greater power of regeneration 
after injury than is possessed by the purely motor cells 
and so may lead to the occasional restoration of modi- 
fied reactions (RD) in advance of voluntary power or 
normal reactions. 

Among the muscles damaged by infantile paralysis 
three degrees of injury may be noted. In one the 
muscles are thin, but they present reactions, which 
though weak are normal in quality both to the indue- 


tion coil and to the battery current. In the second 
group the muscles are paralysed, atrophied, and show 
a reaction of degeneration, while the third group show 
no visible reactions at all. 

It cannot fairly be said of the first group that they 
will recover spontaneously, for there are many which 
do so very imperfectly. Under treatment they usually 
begin to progress from the first, and become much 
strengthened even when the affected limb has been 
much thinner and weaker than its fellow. 

It is well known that muscles paralysed by polio- 
myelitis may recover spontaneously, but there are many 
others which remain in a state of very imperfect re- 
covery, even though their electrical reactions are nor- 
mal, and these derive benefit from systematic electrical 
treatment. I have seen improvement start at once 
with treatment in a case of fifteen years standing, pre- 
viously untreated. 

With cases of the second class, namely, those with 
great atrophy, paralysis and the reaction of degenera- 
tion it is quite a mistake to say that they are incurable, 
and that electricity can do nothing for them. Electrical 
reactions of normal quality, and useful voluntary power 
may return in muscles which for a long time have 
shown RD and loss of voluntary power, and this I have 
seen a number of times. 

In a child with a history of paralysis which came on 
at the age of 4-I- months, treatment commenced in June, 
1891 ; she was then 3 years of age. There were no 
reactions in any muscles of either leg, there was extreme 
wasting, and marked talipes equino-varus in the left 
foot. She was quite unable to stand. After three 
years treatment her legs showed reactions to the induc- 
tion coil in nearly all the muscles on both sides, and 


she could walk, though this was done in a rather 
awkward manner, because one quadriceps extensor 
muscle continued very thin and weak. This case 
affords a clear instance of the good effect of electrical 
stimulation upon the nutrition of greatly enfeebled 
muscles, which at one time seemed to have fallen into 
the last degree of atrophy and paralysis. 

I have notes of numerous cases in which normal 
reactions and voluntary power have returned in muscles 
long paralysed with RD. 

The following illustrates the class of case : — 

C. F., onset of paralysis in 1894, when seen in the 
same year there was RD in front muscles of right leg, 
with feeble normal reactions in the peronei, and no 
reaction of any kind in calf or tibialis posticus. Next 
year there was slight return of voluntary power. In 
1899 voluntary power much greater, and normal reac- 
tions of ~ good quality in peronei and front muscles with 
return of reaction (RD) in calf and tibialis posticus. 

The routine treatment with infantile paralysis should 
be as follows : — At the first visit the muscles are tested 
carefully and the result is recorded, the girth of the 
affected limb is measured, and the voluntary power of 
the paralysed muscles ascertained, and any faulty atti- 
tude of the limb noted. A note must also be made of 
the colour of the limb, its temperature, and whether 
chilblains or scars are present or not. The mother or 
the nurse is instructed how to carry out the electrical 
treatment with coil bath, and she is further told to rub 
the affected limbs every night for a quarter of an hour. 
If irons or other orthopaedic appliances are worn the 
child is to be made to exercise its limbs without them 
for a certain time every day. She must also be shown 
how to exercise the muscles which are weak, by means 


of appropriate movements, and must take pains to make 
the child try to do its best to move the hmb accord- 
ingly. By impressing upon the parents the need for 
patience and perseverance, one is able to ensure their 
co-operation, and this is the most important factor of 
all. The nurse or mother must carefully be taught how 
to regulate and manage the coil. The induction coil is 
the best instrument for use in these cases. In addition 
to the coil bath a short application to the weakest 
muscles by means of electrodes may be advised when 
the management of the case is in intelligent hands. 
The coil or the battery current can be used for this as 
may seem most advantageous and it is best that this 
part be reserved for the medical man's own application. 
A constant battery is not very suitable for domestic use. 
The medical man must make periodical testings and 
examinations to see how the case progresses. 

The first signs of improvement are a better circula- 
tion in the affected parts, disappearance of chilblains 
and sores, and a gradual gain of voluntary power. 

The return of electrical reactions comes later, and it 
is common when all contractility has been lost for the 
normal reaction to the induction coil to return without 
an intermediate stage of contraction to galvanism only. 
This means that the few latent normal fibres in the 
wasted muscle have begun to grow and gain sufficient 
strength to produce a visible contraction. 

When the lower limbs are the seat of the paralysis 
the electric bath is a much better method than direct 
applications of the electrodes to the paralysed muscles. 
An ordinary wooden tub of appropriate size filled with 
warm water is taken, the electrodes in the form of 
plates of metal are suspended at the two ends, and the 
child dressed in a short waistcoat, is put into the bath 


in a sitting position. The current is very well borne in 
this way, and the whole extent of the paralysed parts 
•comes simultaneously under treatment. The strength 
of the current is gauged by putting the hands into the 
tub, one at each end, and by watching the effect upon 
the child, the current being weak at first, and strength- 
ened gradually. It must not be so strong as to cause 
rigidity of the muscles. This plan requires no special 
-knowledge of anatomy, it is efficient and likely to be 
persevered in, and this point of perseverance over long 
periods of time is the key to success. Even if only one 
of the lower limbs be affected, there is no reason why 
the bath should not be used, and if the sound leg be 
flexed and drawn up, most of the electrical current can 
be diverted into the affected one. From Debedat's 
observations (§ 189) one would advise that the current 
be interrupted rhythmically at intervals of one or two 
seconds. ~ A very ingenious rhythmic interrupter driven 
by clockwork has been designed by Prof. Bergonie, and 
is made by Gaiffe of Paris.''' 

The following summary represents the writer's views 
upon infantile paralysis : — 

1. In every case of infantile paralysis which is not 
clearing up satisfactorily, it is important to apply elec- 
trical treatment, continuing it for six months or a year 
or more. 

2. It is the exception for a muscle to be so completely 
destroyed by poliomyelitis as to be left without any 
functional fibres, and these remaining iibres can be 
cultivated by persevering stimulation of them. 

3. Where the muscles show only the reaction of de- 
.generation or are even entirely abolished, some improve- 
ment may be hoped for. 

* Archives d'elect. med., 1896, p. 66. 


4. The amount of restoration which is possible in a 
muscle will depend upon the number of surviving gang- 
lion cells. With patient treatment recovery advances, 
very much farther than one might expect, and is in- 
finitely superior to the results obtained when treatment- 
has not been given. 

5. Even where the electrical reactions are not altered 
in quality, it is not good practice to leave the case to- 
take care of itself. 

In electricity we have a stimulating treatment, which 
is superior to any mechanical stimulation by rubbing 
or massage. It may advantageously be combined with 
these. The form of electrical stimulation to be em- 
ployed is less important than the need for perseverance. 
As a rule the induction coil meets the requirements of 
the case, and when used in conjunction with the bath is 
quite easily arranged for use by the mother or nurse of 
the patient. 

The distribution of the paralysis produced by acute 
anterior poliomyelitis is peculiar, some muscles are 
affected very much more commonly than others. 

In the first place the lower limbs are the seat of para- 
lysis more often by far than the upper. In the lower 
limb the muscles of the leg are very frequently damaged, 
especially the peronei, the tibialis anticus, and the calf 
muscles ; the quadriceps extensor cruris is also rather 
apt to suffer ; and if the paralysis affect all its parts 
seriously, the whole limb becomes very much crippled 
thereby. Except when there is extensive damage to 
the limb the intrinsic muscles of the foot are likely 
to escape, and the same can be said of those of the 

In the upper limb the muscles of the shoulder and 
arm suffer rather frequently. The deltoid is often in- 


jured, and the loss of it cripples the arm very much, 
and it is also a muscle which does not readily improve. 

The deformities which result from the over action of 
muscles, when their antagonists are damaged by this 
disease, are well known. Many of the various forms of 
club-foot originate from infantile paralysis. It may be 
worth while to give briefly the action of the leg muscles 
upon the foot as summed up by Duchenne : — There are 
three pairs of muscles with the function of moving the 
foot upon the leg. i. The calf muscles and the pero- 
neus longus. 2. The tibialis anticus and the extensor 
communis digitorum. 3. The tibialis posticus and the 
peroneus brevis. The first pair extend the foot, the 
second pair flex the foot, and the last pair produce 
lateral movements. 

The movements of flexion and extension by the first 
groups include lateral movements also, because the pull 
of the muscles is not direct. When simple flexion or 
simple extension movements are required, they are pro- 
duced by the combined action of both components of 
each pair ; thus, the calf muscles extend and adduct, 
'while the peronei extend and abduct, the tibialis anticus 
flexes and adducts, the extensor communis digitorum 
flexes and abducts. Of the remaining pair, the one, the 
tibialis posticus, adducts, and the other, the peroneus 
brevis, abducts. There are many other composite 
movements carried out by these muscles, but individu- 
ally considered their actions are those just mentioned. 
The special deformities likely to follow the paralysis of 
any of these muscles, or of any combinations of them, 
can be predicted, if their special action, and that of 
their antagonists, are borne in mind. Operations for 
the correction of the deformities produced by infantile 
paralysis by means of attaching the tendons of impor- 


tant paralysed muscles to the- muscular portions of less- 
important and unparalysed neighbouring muscles have 
been successfully performed. Some of these muscles 
play an important part in preserving the arch of the 
foot, and when they are paralysed a tendency to flat 
foot is well marked. An opposite condition of exag- 
gerated arch of the foot is also known, and was de- 
scribed by Duchenne under the name of griffe pied creiiXy 
or hollow claw foot. Often it is an effect of paralysis 
of the interossei. 

These muscles flex the proximal phalanx and extend 
the distal phalanges of the toes by a single movement, 
they also produce lateral movements of the toes. Their 
action supplements those of the other flexors and ex- 
tensors of the toes. The long flexors flex only the 
distal phalanges, while the extensors, extend only the 
proximal phalanx. In the absence of the antagonising 
action of the interossei the long extensors extend the 
first phalanges permanently, and the long flexors flex 
the second and third phalanges also permanently, and 
this produces a claw-like attitude of the toes. The 
abductor and flexor brevis of the great and of the little 
toes act in a similar way, and when they are paralysed 
the claw shape becomes more intensified. 

The hollow claw foot or pes cavus is not very often 
developed as a sequel to infantile paralysis, if it does, it 
is generally unilateral. Cases of double pes cavus, from 
their history and the associated symptoms, seem to 
be probably due to spasm of the long flexors and exten- 
sors of the foot and not to paralysis of the interossei 
(see § 218 below). 

191. Progressive muscular atrophy. — Before con- 
sidering the electrical treatment of this disease, it may 
be worth while to discriminate between the various 


states of muscular atrophy which have been formerly 
confounded under this name. These are "myelopathic" 
atrophies due to changes in the anterior cornua, "neuro- 
pathic " atrophies due to changes in the nerve trunks^ 
and " myopathic " atrophies from changes limited to 
the muscles themselves. True progressive muscular 
atrophy is a type of the first class, and pseudo-hyper- 
trophic paralysis of the third, while various forms of 
atrophy due to neuritis require to be considered in the 
second class. Indeed the lines of demarcation between 
different groups have not always been drawn with pre- 

In none of the diseases included in the general title 
of progressive muscular atrophy can it be said that the 
prospects of cure by electricity are good. Still in de- 
fault of any other better method of treatment it is 
reasonable to believe that the use of electricity is a step 
in the right direction, and it is quite right that efforts 
should be made to obtam relief by means of electrical 
treatments In the spinal forms Erb considers that he 
has seen relief, retardation, and even arrest of sym- 
ptoms, especially in early cases, and advises treatment' 
of the spinal cord, particularly the cervical enlargement, 
which is so frequently the seat of the most severe 
atrophic changes. His method is to use the battery 
current, applied to the cervical spine, the cervical sym- 
pathetic, the lumbar enlargement and the peripheral 
nerves. He insists especially upon the importance of 
the action of both poles being brought to bear suc- 
cessively upon the affected regions of the cord. Finally, 
the affected muscles are to be treated by the induc- 
tion coil current. The current should be "moder- 
ately strong," but too vigorous a treatment is not, 


Erb also says that although electrical treatment may 
.arrest or retard the progress of the disease, that yet it is 
in no way a cure, and that the curative results said to 
have been obtained are generally the consequence of 
errors of diagnosis, especially in cases of neuritis, in- 
fantile paralysis, and atrophy after joint affections. He 
considers that the myopathic atrophies have a more 
favourable prognosis, as he has seen great benefit follow 
electrical treatment in long standing cases of that kind. 
Duchenne wrote that by means of induction coil treat- 
ment he had been able to arrest the progress of the 
disease in an advanced case,''' to re-establish the power 
•of the diaphragm, which had become seriously involved, 
to restore the bulk and vigour of an important muscle 
(the biceps), to dispel the fibrillar twitchings, and that 
the recovery was persistent for several years, in spite of 
the fact that the patient returned to hard manual labour, 
a condition of things extremely likely in Duchenne's 
opinion to bring on a relapse. He is certain that he 
has seen an increase in the bulk of a wasting muscle 
from coil applications, but only in cases where the 
muscle had not altogether lost its irritability to coil 
currents. He lays down precise instructions for the 
method to be adopted as follows : — 

1. To pass the moistened electrodes over the surface 
of each of the affected muscles, keeping them close to- 
gether, and using a current of low electromotive force. 

2. To stimulate the muscles moderately, and with a 
current which is not interrupted very frequently. 

3. To treat only the muscles which react to the coil, 
and to pay most attention to the most important 

* The case which seems to have been undoubtedly one of "myelo- 
pathic" progressive muscular atrophy, is described and figured, 
" Elect, localisee," 3rd edit., p. 500. 


muscles, and to terminate the sitting by a mild appli- 
cation to any muscles which may be threatened with an 
invasion of the disease.''' 

Treatment of the spinal cord itself should be care- 
fully tried in these cases, as the mere treatment of the 
muscles does not appear to be very promising. 

The electrical reactions in progressive muscular 
atrophy are a little complicated, because the gradual 
destruction of the muscle, fibre by fibre, produces a 
condition in which, while some fibres react normally, 
others respond only by a reaction of degeneration. It 
may sometimes be possible to recognise a sluggish con- 
traction appearing after the quick contraction, the latter 
being produced by the sound fibres and the former by 
those which are degenerated. 

192. Locomotor ataxy. — The value of electrical 
treatment in this disease is not yet settled. At the 
same tinie it is certainly premature to dismiss elec- 
tricity as useless in all stages of this complaint, although 
it is no doubt correct to say that in advanced cases of 
the disease electricity will not restore the tissues which 
have perished. A difficulty which meets one at the 
outset is the natural tendency of the disease to become 
arrested in certain cases, particularly in those which 
come under treatment early. Thus I have notes of a 
patient who had lightning pains, loss of knee-jerk, 
occasional diplopia, slight ptosis, and unsteadiness on 
closing the eyes, and in whom the existence of tabes 
was suspected by myself, and confirmed by the opinion 
of a leading neurologist. This patient returned home 
and was vigorously treated with anti-syphilitic reme- 
dies, and I have been informed since, on several occa- 

* For the muscles most usually attacked, see Duchenne, op. cit., 
p. 494, or Gowers' " Diseases of the Nervous System," p. 359. 

A A 


sions, and at intervals of two or three years, that he has 
recovered good health and is leading an active life. 
There was no electrical treatment in that case. 
Another patient of mine, a police officer, with many 
signs of tabes, quickly lost his symptoms during a 
course of electric baths. Many writers on electro- 
therapeutics have been able to bring forward instances 
of relief to symptoms from electrical applications in 
tabes. In the Arch, d' electvicite medicale of 1893, the 
notes of thirty-two cases are collected together from 
various sources by Dr. Laborde, and the whole subject 
of the electrical treatment of tabes is critically exam- 
ined in a paper which forms a valuable contribution to 
the subject. His summary is that in his own experi- 
ence the treatment of the spinal cord by continuous 
currents does not cure tabes. In certain cases it may 
relieve the pains, the ocular troubles, or the weakness 
of the limbs. Induction coil currents seem to act un- 
favourably. x\ further study of the subject is desirable. 
193. Injuries of nerves. — In injury and disease 
of the nerve trunks the natural tendency to recover is 
strong, and stimulation by electricity certainly hastens 
their recovery very much. It has been said of electrical 
treatment that the cases which do well under it would 
do equally well if they had been left untreated, and this 
has often been the excuse for the neglect of electrical 
methods. Even if this assertion were true, which it 
certainly is not, it applies with equal force to most of 
the drug treatments which medical men so complacently 
prescribe for their patients. But it would be out of 
place in this book to criticise the habit of mind of 
medical practitioners. 

The following case illustrates the value of electrical 
treatment in a case of traumatic neuritis of the musculo- 


Spiral nerve. A gentleman, by sitting for a long time in 
one position in an arm-chair, compressed the musculo- 
spiral nerve, and numbness and weakness of the hand, 
with wrist-drop, was produced. There was no treat- 
ment for several weeks, and there was no improvement. 
I was then asked to see him ; he had paralysis with 
partial RD in all the extensors of the wrist and fingers ; 
the supinator longus was also paralysed and there was 
impaired sensation over the back of the forearm and 
hand. The nerve trunk was tender to pressure at a 
point about half way up the humerus. 

Electrical treatment was commenced and at the end 
of a fortnight the patient had gained considerably in 
voluntary power and appeared to be on the high road to 
recovery. Electrical treatment was therefore suspended. 
He was instructed to rub and shampoo the limb daily, 
and to exercise the muscles, and was told that he might 
expect the process of recovery to continue, even without 
further electrical treatment. A fortnight later he wrote 
saying that he had, made no progress since the last visit. 
Electrical treatment was accordingly resumed, and 
again he began to improve rapidly, and was completely 
well in another fortnight. 

Again, take the following instance of an Erb's para- 
lysis. A man fell into a ship's hold in January, 1898, 
and paralysed the muscles of the upper arm. In the 
follow^ing year, March, 1899, he applied for relief, was 
seen and tested ; a rupture of the 5th and 6th cervical 
cords of the brachial plexus was diagnosed, and an 
operation was performed for reunion. After the opera- 
tion he disappeared from view for a time and did not 
return until November. There was no recovery of 
power. The limb hung helpless from his shoulder. 
He was referred to the Electrical department and a test 



showed a faint reaction of degeneration in the deltoid 
biceps and supinator longus. In the previous March 
when tested before the operation there were no reac- 
tions at all in these muscles. It was judged from the 
return of these faint reactions (RD) that reunion must 
have taken place after the operation, and electrical 
treatment was accordingly commenced. Improvement 
began immediately. After three months he had gained 
enough to do a little work on light jobs and improve- 
ment was still in progress. 

For those who are not unwilling to be convinced 
these cases seem to offer satisfactory evidence that the 
electrical treatment played an important part in " cur- 
ing " the paralysis, and answer the objection mentioned 
above, an objection which is not always easy to meet 
because for obvious reasons it is difficult to combat it 
by direct proof. 

All those who have had practical experience in the 
matter have seen cases of nerve injury begin to recover 
rapidly under electricity after having been stationary 
for long periods of time under " expectant " treatment. 

The simplest cases of peripheral paralysis are those 
which follow injury to the nerve trunks. These cases 
are common, and are sometimes of great interest from 
the exercise in applied anatomy w^hich their diagnosis 
affords. The shoulder and upper limb are their most 
frequent seat. The chief causes of injury to the nerve 
trunks are contusions or lacerations, compression pro- 
duced in various ways, and wounds with sharp instru- 
ments. Falls or blows upon the shoulder, and disloca- 
tions of the shoulder joint commonly produce paralysis 
of the muscles of that region. Pressure, as from the 
use of crutches or from the weight of the body upon the 
arm during sleep, often produces paralysis of the mus- 


cles supplied by the musculo-spiral nerve, and incised 
wounds of the forearm and wrist often lead to paralysis 
of the muscles supplied by the ulnar and median nerves. 
In all cases of this kind electricity is of great use, both 
for treatment and for diagnosis ; and favourable results 
may be expected in almost all cases unless the nerve 
trunks have been actually severed, or are involved in 
cicatricial tissue. In that case surgical measures for 
the union of the divided nerve, or to relieve it from its 
surroundings, are necessary before recovery can be ex- 

From what has been said in §§ 136 to 139 it follows 
that injuries of nerves are likely to be followed by the 
reaction of degeneration in the muscles which they sup- 
ply, and this does always follow if the injury to the 
nerve has been sufficiently severe. But, as such in- 
juries may be of any degree of severity, it will be found 
that the reaction of degeneration is not invariably pro- 
duced, for in the slighter cases the nerve recovers be- 
fore degenerative changes have had time to follow, or 
indeed the injury may be of such a kind as to impair 
both motor and sensory conduction for a time without 
interfering with what may be called the trophic con- 
ductivity of the nerve trunk or setting up an actual 
neuritis. The partial reaction of degeneration is not 
uncommon in cases of nerve trunk injury. 

In the examination of cases in which an injury to a 
nerve is suspected the anatomical details of the nerve 
supply must be carefully kept in mind. 

The phenomena produced in marked cases of injury 
to nerves are loss of motor power, impairment or loss or 
perversion of sensation, and diminished temperature in 
the area of distribution of the nerve with changes in 
the muscles, such as simple diminution of electrical 


excitability, or complete or partial RD, and trophic 
changes in the skin. The " glossy " skin of nerve trunk 
disease is well known, and easily recognised. It 
signifies irritation of the nerve trunk. 

When it occurs in the upper extremity the skin 
of the hand and fingers becomes altered in colour and 
shiny, the finger ends become bulbous, and the nails 
defective. There is an alteration in the appearance of 
the wrinkles and folds over the knuckles, which can 
readily be recognised on comparing the affected with 
the sound side. 

194. Neuritis. — The paralyses which follow wounds 
and injuries of nerves offer an excellent field for useful 
electrical treatment, and the same is generally true of 
neuritis coming on in the course of disease. The 
clinical importance of neuritis is much more clearly 
recognised to-day than it was a few years ago, thus 
justifying the words of Remak in i860, when he wrote, 
" I am convinced that medical practitioners will soon 
recognise that neuritis is a pathological condition which 
occurs more frequently than is usually believed." At 
the present time the public are beginning to adopt the 
word, and to speak of their "neuritis," where formerly 
they would have spoken of their " rheumatism." 

In the electrical treatment of neuritis the question of 
the choice of method turns largely upon the presence or 
absence of severe pain or of acute symptoms. Clinically 
one meets with cases of neuritis with niarked paralysis 
and little or no pain, while in others there is much pain 
and little or no paralysis. In the acute and painful 
cases the direct current is indicated, in the less acute 
and paralytic cases the alternating (coil or sinusoidal). 
Some writers would further divide the paralytic cases 
into two classes namely those showing the reaction of 


degeneration with loss of coil reactions and those in 
which coil reactions were not lost, and they would 
advise the battery current for the first of these and use 
the induction coil current for the latter class only. 
That view is not supported by experience and has 
already been dismissed in § 147 and need not now be 
re-opened, see also § 165 for the indications for the use 
of bath or arm-bath modes of application, as these are 
often very useful in the treatment of neuritis. 

If the neuritis is a general one, or is due to a general 
cause, even though its manifestations are local, the bath 
should be chosen whenever it is to be had. Thus, the 
toxic forms of neuritis, as for example, neuritis from 
alcohol, arsenic, lead, &c., and neuritis following diph- 
theria, influenza or other general infections can best be 
treated by the general bath and the alternating or inter- 
rupted current. I have obtained the most satisfactory 
results in cases belonging to all these classes from the 
bath with sinusoidal current, and regard that form of 
application with the greatest favour. No doubt the 
general bath promotes the elimination of poisons in 
addition to its action upon the damaged tissues, (see 
also § 146). 

195. Neuritis from lead poisoning. — In paralysis 
due to lead the reaction of degeneration is usually pre- 
sent, and is an early symptom. The partial reaction of 
degeneration is also often seen in some of the affected 
muscles, and others may show only simple quantitative 
diminution. Erb has pointed out that from the long 
duration of lead paralysis and the frequently occurring 
relapses, the condition of the electrical excitabihty may 
be considerably complicated. In cases of long standing 
the reactions become very difficult to elicit. Treatment 
by electricity is of prime value, for muscles which have 


lost their electrical irritability almost completely may 
be seen to recover it under this treatment, which needs 
to be long continued to obtain good results. Although 
some writers have advised the constant current almost 
exclusively in lead cases, Duchenne long ago showed by 
practical trials that a cure can be effected by coil 
currents also. He stated that in lead palsy recovery 
will follow the treatment almost always, even if the 
irritability to the induction coil current has completely 
disappeared from the muscles. 

For the ordinary type of case with wrist drop, treat- 
ment by means of the arm-bath and alternating currents 
is always followed by improvement, and recovery will 
be complete except in old broken-down patients where 
the affection is of old standing. In more severe cases 
with extensive paralysis the full length bath is to be 
preferred and this may be combined wdth direct current 
applications to the worst muscles. To determine which 
of the extensors of the wrist are affected, the patient is 
told to raise the forearms and pronate them. If the 
muscles are all three of them paralysed there is then no 
power of extending the wrist at all. If the extensor 
carpi radialis brevior can act, extension of the wrist is 
possible when the fingers are first flexed. If only the 
extensor carpi radialis longior, or the extensor carpi 
ulnaris, can act, then slight extension is associated with 
a lateral movement to the side of the acting muscle. 
Although the supinator longus usually escapes in wrist 
drop due to lead, it does not always escape. In the 
lower limbs the peronei seen especially prone to become 

It is extremely important when the lead poisoning is 
a result of the patient's occupation that he should be 
advised to give it up altogether, otherwise relapses are 


almost certain to follow his return to work. When the 
patient returns to his occupation partly cured, he is 
almost certain to relapse. 

196. Arsenical neuritis. — General neuritis may be 
produced by arsenic in medicinal doses or it may follow 
a single large dose. As an instance of the latter the 
following is of interest. A prison warder in Ceylon was 
poisoned by a dose of arsenic in May, 1896. He sur- 
vived the immediate effects of the poison, although they 
were very severe, and six days later felt numbness of 
the extremities which extended until there was general 
loss of power. He could not stand, nor feed himself 
nor button his clothes. The bladder was not affected. 
In October he came to England and could then stand 
and walk a little. Knee jerks were absent, reactions 
showed partial RD in many muscles of the lower limbs. 
Upper limbs normal in quality. He was treated by 
general "electrification (sinusoidal baths) and quickly 
responded ; but it was not until June of the following 
year that he was fully recovered. He is noted to have 
shed the nails of his toes several times during his 

A case of poisoning from arsenic given medicinally is 
the following : — A girl aged 10, with chorea to whom 
arsenic had been given in ten minim doses for five 
weeks, became paralysed in all her limbs. The legs 
were most affected and the front muscles more so than 
the calf or peronei. RD was present. There was great 
wasting, some pigmentation of the skin and great pain 
in the limbs. She made a good recovery, the girth 
measurement of the calf increasing by two and a half 
inches between IMarch and November. 

Dr. Colman" has reported a similar case, also in a 
* British Medical Journal, January, 1S98. 


girl of twelve years who was treated for chorea with 
arsenic during a month, the daily dose being equal to 
forty-five minims of liquor arsenicalis. At the end of 
that time the chorea had ceased and the child seemed 
in good health, but a fortnight later she had complete 
paralysis of the extensors of the feet, with RD, and 
partial paralysis of the extensors of the wrist and fingers 
with simple decrease but no RD. She recovered under 
the influence of rest, massage and electricity. 

197. Alcoholic neuritis. — General electrification by 
means of the bath and sinusoidal or induction coil 
current gives excellent result in these cases. I have 
notes of several severe and typical cases in women 
where the patients at the commencement of the treat- 
ment were quite helpless, with marked reaction of de- 
generation in many muscles, but began to improve at 
once, and recovered good voluntary power, normal re- 
actions and well nourished muscles during the time of 
their electrical treatment. It may be said of this dis- 
ease, as of so many other forms of neuritis, that it 
has a natural tendency towards recovery provided that 
alcohol can be withheld and the patient managed on 
general principles, but this does not in any way detract 
from the advantages to be derived from electrical treat- 
ment, which has a most distinct effect in promoting and 
hastening the recovery of the lost power. 

The presence of great pain in a case of neuritis is a 
contra-indication for brisk electrical stimulation, and 
the induction coil current is not so well borne as the 
sinusoidal when pain is marked. In these cases a 
direct current, either in a bath or applied by electrodes, 
may be used at the commencement of the course, with 
a change to the alternating current and the bath, begin- 
ning gently, as soon as it can be borne with comfort. 


A point is soon reached when the latter form of current 
gives ease and reUef, even though a good deal of pain 
and tenderness still exists in the limbs. 

Besides the typical cases of alcoholic neuritis one 
may often observe cases of a local neuritis (traumatic 
or other) in which alcohol is a predisposing cause or is 
acting prejudicially. The influence of alcohol in delay- 
ing recovery in cases of simple traumatic neuritis may 
be very commonly observed (see also § 214). 

In other cases it may be difficult to decide whether a 
neuritis is primarily due to alcohol or to some other 
cause, as for example, gout, for both influences may be 
at work in the same case. 

198. Gouty neuritis. — What has been said of alco- 
holic neuritis and its electrical treatment applies with 
equal force to gouty neuritis. The general bath method, 
the local bath, or finally, the direct use of the constant 
current in cases with much pain, may all be employed 
with advantage in gouty cases. The use of local baths 
with lithium salts dissolved in the water has been 
already referred to in §§ 125 and 167. The local treat- 
ment of a neuritis due to gout is likely to prove ineffec- 
tive if the patient is allowed to continue in a general 
gouty condition, with recurrent articular attacks. On 
this account general electric treatment is an important 
means even for a local gouty neuritis, and treatment by 
diet and by drugs must also be attended to. Some 
cases of " sciatica " are due to gouty or alcoholic 
neuritis and a reaction of degeneration may occasion- 
ally be found in them if looked for. 

igg. Rheumatic neuritis. — The term "rheumatic" 
has been applied to facial paralysis coming on after 
exposure to cold, and to other instances where exposure 
to cold or wet has appeared to be the direct cause of a 


neuritis. Sciatica is probably in many cases a form of 
rheumatic neuritis. Neuritis of the circumflex nerve, 
the so-called "deltoid rheumatism" is another. The 
special methods of electrical treatment in these condi- 
tions will be dealt with under their respective headings. 

Gonorrhoea has been recorded several times as a 
cause of neuritis. A recent case well reported, with 
many references, will be found in the Arch, cf electricite 
mt'dicak, June, 1898, by Dr. Allard. The patient had 
loss of power in the lower limbs, impaired sensation in 
the same regions, with pain and tenderness of sciatic 
and crural nerves and showed great simple decrease to 
coil and to cells in the muscles of the legs but no RD. 
The symptoms came on a fortnight after the appearance 
of a discharge, and were followed a few days later by 
inflammation in one ankle joint. The neuritis was 
treated by electricity. The patient recovered. 

200. Septic neuritis. — A form of neuritis which is 
very painful, and very slow to yield to treatment is that 
which occurs in parts which have been the seat of 
suppuration, and is not uncommon after whitlows or 
poisoned wounds of the hand. The crippled condition 
which is left in these cases, though partly due to a 
matting together of ligaments and tendons, is also in 
part due to the existence of neuritis. Sometimes it is 
difficult to decide whether nerves may not have been 
divided in the incisions necessary for the evacuation of 
abscesses, and electrical testing should be called in for 
an answer. But although incisions may sometimes 
have divided some branches of the nerves and in that 
way may have contributed to the paralysis, it is gene- 
rally possible to show by electrical testing that neuritis 
exists in the areas of nerves which cannot have been 
injured by the knife. For example with an incision 


which seems to have been dangerously near the median 
or the ulnar trunk in the forearm or at the wrist:, a 
testing may show that the ulnar or the median intrinsic 
muscles are damaged in unequal degrees. In such a 
case one could infer that there was no severing of the 
nerve trunk, and that the symptoms were due to some- 
thing more distally situated. Again one may be asked 
whether the loss of power is due to an actual inflam- 
matory process in the nerves, or whether it may not be 
due to compression of the nerves by cicatricial tissue. 
To answer this question one must look for signs of 
neuritis outside the area in which such cicatricial com- 
pression can be effective. 

In painful amputation stumps we have another in- 
stance of septic neuritis, and in these cases there is 
often clear evidence of a neuritis extending upwards 
beyond the area of the scar. 

The electrical treatment of these cases is slow. I 
have notes of several of them who have attended for a 
a twelvemonth before completely losing their pains. 
Some relief is quickly felt from the applications, which 
are best carried out by means of the arm bath with the 
sinusoidal current or the continuous current, the latter 
being perhaps superior to the former. Although the 
results come so slowly it is none the less surely. 
Gradually the texture and aspect of the skin return 
to normal, the adhesions soften and the pain diminishes 
progressively and disappears. 

The occurrence of a local attack of neuritis in the 
course of diseases which are apt to be associated with 
septic or saprsemic states is not very uncommon. It is 
probable that some of the cases of neuritis described by 
Dr. Turney"''' were really of this kind. Cases have been 
* St. Thomas'' Hospital Reports, iSg6, vol. xxv. 


described by numerous writers. I have myself seen 
one, probably of this class, in which a facial paralysis 
developed after confinement. Its symptoms differed in 
several points from ordinary "rheumatic" facial para- 
lysis. It was associated with pain and numbness in 
the side of the face, and recovered very slowly and 
imperfectly. There was no exposure to cold nor ear 
disease or other local mischief to account for its coming 
on. Again, a patient who was being treated for stric- 
ture by the passage of catheters, was taken ill with 
fever for which he was admitted into Guy's Hospital. 
On his recovery he came to St. Bartholomew's Hospital 
with a paralysis of the right serratus magnus which had 
come on during his illness. He made a good recovery. 
This case I believe to have been a neuritis of septic 
origin affecting the posterior thoracic nerve. 

201. Neuritis from syphilis. — Neuritis is some- 
times met with in syphilis, and the following is a 
striking case : — A man came under treatment in Decem- 
ber, 1892, with partial paralysis in the right arm. 
There was marked wasting of the biceps, and the grasp 
was much diminished in power. He had pains on the 
inner side of the arm. On his chest was an indolent 
late syphilitic patch of ulceration. In two months he 
had recovered, but not long afterwards he returned 
with sciatica, and a few months later came again with 
a recurrence in the other sciatic nerve. In 1894 ^^^ 
reappeared w4th facial paralysis. Finally, in 1896, he 
came for the last time with hemiplegia. He was in a 
wretched condition and had been laid up several months 
in a country infirmary. Since then he has not been 

It is difficult to estimate the value of electricity in 
syphilitic neuritis because the drug treatment in this 


disease is of decided value. Electrical applications are 
probably useful, and should certainly be employed as 
an adjuvant in all cases. 

202. Neuritis after specific fevers, diphtheria, 
influenza, 6cc. — These cases may show an extensive 
implication of nerves or only a local neuritis. It is 
probable that in all of them the general effect of the 
electric bath is useful, by reason of the general toxaemic 
condition, upon which they depend ; but good results 
may be expected from local treatment when the neuritis 
itself is purely local. It may not be out of place to 
mention that neuritis is not the only nervous disorder 
which may complicate or follow the specific fevers. 
Hemiplegia, disease of the lateral columns of the cord, 
or of the anterior cornua may also occur, and as all of 
these conditions are decidedly more unfavourable than 
simple neuritis, it is important to make sure of the 
position and diagnosis in every case. Moreover, it may 
happen that a neuritis following a specific infection will 
persist in the most obstinate way in spite of all treat- 
ment. They do not all clear up quickly and thoroughly. 

- For example, I would mention a case of simple neuralgia 
of one anterior crural nerve which followed an attack of 
influenza and only wore away gradually and slowly, ap- 
parently uninfluenced by treatment, and took a twelve- 
month before its complete disappearance. Happily 
such unfavourable cases are not the rule. 

After typhoid fever a local neuritis is not very rare. 
It is possible that some of the slighter cases of local 
neuritis after severe illness may be of the nature of 
pressure paralysis or sleep paralysis (see § 214). 

203. Neuritis as a disease of women. — Neuritis 
has been noted as coming on during pregnancy, and 
also during the puerperal slate. At the menopause also, 


symptoms of neuritis, especially numbness, tinglings, 
and pains are frequently complained of. Dr. Turney 
in his paper on " Polyneuritis in relation to Gestation 
and the Puerperium "" seems disposed to classify the 
disease as a form of neuritis, due to some form of auto- 
intoxication. A difficulty which he fully recognises is 
the difficulty of excluding other causes of neuritis, but 
even after the doubtful or uncertain cases are separated 
there still remains a considerable weight of evidence in 
support of his views. Cases of neuritis at the meno- 
pause are not very uncommon if one is willing to accept 
as evidence of neuritis the symptoms of numbness, mus- 
cular weakness, &c., so often complained of by women 
at that period of life. Occasionally one meets with 
stronger evidence in the shape of muscular atrophy, 
though this is not common. Many female patients 
between forty and fifty years old are referred to the 
electrical department every year for treatment for pains, 
numbness and weakness affecting the hands, a condition 
which we are now accustomed to recognise as a neuritis 
due to the menopause. Under the arm-bath treatment 
they recover after a longer or shorter time. 

204. Special paralyses. The ocular muscles. — 
Paralysis of these muscles may be treated by electricity. 
Occasionally from exposure to cold a paralysis of some 
of the ocular muscles is set up of a similar nature to the 
ordinary " rheumatic " facial paralysis. 

Treatment is complicated by the difficulty of reaching 
the muscles. Their deep-seated position, the proximity 
of the retina, and the sensitiveness of the conjunctiva 
all help to make it practically impossible to excite con- 
tractions in them. 

It has been proposed to use a fine electrode and in- 
* St. Thomas^ Hospital Reports, vol. xxv. 


troduce it into the conjunctival sac after that has been 
rendered insensitive by cocaine. Good results have 
sometimes followed a longitudinal treatment of the skull, 
the kathode being placed stabile upon the closed eyelid. 
A current of i to 5 milliamperes, and a duration of 30 
to 60 seconds, are recommended by Erb. Dr. Buzzard 
has recommended the use of the index finger covered 
by damp muslin as the active electrode (see § 151, hand 
electrode) or small sponges may be used. They are 
soft and readily adapt themselves to the surface of the 
eyelid. The reflex effect of applications to the skin 
of the face may also be tried, as recommended for the 
treatment of facial paralysis. Dr. Buzzard has reported 
two cases where permanent improvement did follow the 
constant current. Electricity is not likely to be of much 
use in the treatment of ocular paralyses. 

205. Facial paralysis. — This is a common form of 
paralysis, ~ and very frequently comes under electrical 

If we except those cases of paralysis of the facial 
muscles which form part of hemiplegia the remainder 
usually depend upon disease of the nerve trunk or of its 
nucleus of origin, and of these the commonest seat is 
in the nerve-trunk, and the part of the nerve which is 
usually at fault is that which passes along the Fallopian 

In this part a very little swelling of the nerve or of 
the walls of the aqueduct is sufficient to cause com- 
pression of the nerve fibres. Disease of the ear and 
exposure to cold are the commonest exciting causes. 

The reaction of degeneration is present in a large 
number of cases of facial palsy, and a case carefully 
watched and treated from the commencement offers one 
of the best introductions to the subject of electrical 



diagnosis and therapeutics, and the disease has been 
much studied from this point of view. The phenomena 
of the reaction of degeneration were first observed by 
Baierlacher in cases of facial palsy (see § 136). In all 
but the slighter cases the reaction to the induction coil 
disappears within the first week. If the patient is 
tested daily, the gradual development of the RD will 
be clearly seen. In testing a case of facial paralysis it 
is well to bear in mind that the skin of the face is sensi- 
tive, and that the muscles are near the surface, strong 
currents are therefore unnecessary, and must be avoided. 
For the importance of the electrical reactions in prog- 
nosis, see § 140. Even in the worst cases of facial 
paralysis of the ordinary kind, if there be no progressive 
disease involving the nerve, it is usual for some re- 
covery to take place, and it is not uncommon for the 
recovery to take place unequally, thus the upper part of 
the face may improve faster than the lower or vice versa. 
Old broken down patients do not do so well as younger 
people". A considerable proportion of cases of facial 
paralysis occurs in young women ; they are excellent 
cases for study as they attend with the greatest dili- 
gence until completely recovered. 

If a case of simple facial paralysis receives no elec- 
trical treatment its rate of recovery will be slower than 
if it be assiduously treated, and the same is true of 
cases where the electrical treatment is too feebly car- 
ried out, and this is sometimes apparent when through 
the timidity or sensitiveness of the patients, very weak 
currents are employed, and the recovery is delayed. 
The cases of facial paralysis from ear or bone disease,, 
or from nuclear mischief are naturally more unfavour- 
able than those coming on from " cold." The hemi- 
plegic cases usually recover fairly without treatment.. 


Care must be taken to exclude all probable unfavour- 
able causes of the paralysis before making a favourable 
prognosis. All unusual cases are to be regarded with 

The electrical treatment should be in accordance with 
what has been laid down for paralysis in general, viz. : 
direct treatment of the seat of the lesion and of the 
affected nerve and muscles, and reflex stimulation of 
the skin of the face ; treatment may be commenced at 
once. For reaching the injured part of the nerve trans- 
verse applications to the skull are advised with the 
electrode behind or below the ear. Then the nerve and 
muscles may be treated with the kathode, each of the 
main branches of the nerves being stroked in a labile 
manner from centre to pheriphery, and each muscle 
being treated with the same pole for half a minute, the 
anode being at the nape of the neck. Lastly, the skin 
of the face and the muscles may be treated with the 
induction coil. 

206. The trapezius and sterno-mastoid. — Para- 
lysis and atrophy of these muscles follow injury or 
disease affecting the spinal accessory nerve or its 
nucleus. The trapezius especially may suffer as a 
result of the suppuration of strumous glands of the 
neck, or of the surgical operations for their removal. 

Paralysis of the sterno-mastoid is easily recognised 
if looked for. When the head is turned towards the 
opposite side, the outline of the muscle standing out 
under the skin is plain to see in health but is lost if the 
muscle is paralysed. 

When the trapezius is paralysed there is a general 
feeling of weakness about the shoulder, and a complaint 
of myalgic pains, because the muscle plays so large a 
part in supporting the shoulder during the movements 

BB 2 



of the upper limb. If the trapezii be watched and 
studied in persons who have the neck and shoulders 
bare, it will be seen that these muscles are in almost 
continual action during movements of the arms, and, 
indeed, much of the beauty of the contours of the neck 
and shoulders depends upon the good development of 
the trapezii. 

Fig. tz- — Paralysis of left trapezius. 

When one trapezius is paralysed the difference be- 
tween the two shoulders can easily be recognised, par- 
ticularly if the muscle be wasted as well. On the 
affected side the point of the shoulder is lowered, and 
the line from the neck to the shoulder-tip is hollowed. 
This difference is well seen with the arms hanging at 
the sides (figs. 73, 74). The position of the scapula is 


also changed, for the inner border of the bone does not 
lie parallel to the vertebral column, as in health, but at 
an angle with it, its upper corner being rather further 
from the middle line, and its lower angle rather nearer, 
at a higher level and more prominent. Duchenne has 
explained why this is the case. The shoulder, having 

Fig. 74. — Paralysis of the upper part of the right trapezius. 

lost the support of the upper part of the trapezius, 
hangs as it were suspended by its upper angle from the 
levator anguli scapulae, and turning, as on a pivot, at 
the point of attachment of that muscle, its lower angle 
is tilted inwards and upwards, and the acromion sinks 
downwards by the weight of the arm. In some cases 
of paralysis of the trapezius this tilting upwards of the 



inferior angle is not present. It may even be at a lower 
level on the paralysed side, particularly if the lower part 
of the trapezius is not completely powerless (fig. 74). 

If the patient be told to raise the arms to the head 
another peculiar defect comes into notice ; namely, that 
the clavicle in its outer half comes into view from be- 
hind. This is a valuable diagnostic sign of atrophy of 

Fig. 75. — Paralysis of left trapezius. Clavicle seen from behind. 

the muscle — one which, so far as I can learn, has not 
previously been pointed out, see fig. 75. 

I have seen four cases in which the paralysis was due 
to injury or section of the spinal accessory nerve during 
surgical operations. In the first of these the incision 
was a small one, high up at the posterior border of the 
upper part of the sternomastoid. The nerves were 


carefully considered during the operation, and, as was 
thought, had not been divided. The wound healed 
very well ; nevertheless, the muscle became wasted, 
especially in the upper and middle parts. A small 
band of fibres remained in the position of the clavicular 
portion — the ultiinum moviens of Duchenne — but in this 
there was a marked reaction of degeneration. The 
lower part of the muscle was not quite so much atro- 
phied as the upper part, and the inferior angle of the 
scapula was not tilted upwards. In another case the 
whole of the side of the neck was much scarred, as the 
result of numerous strumous abscesses and of the sur- 
gical treatment for their relief. Both the trapezius and 
sternomastoid on the right side were extremely wasted, 
and the rhomboids were also in same condition. The 
scapula and clavicle seemed inclined to fall forward by 
the action of the pectorals, and in that position the 
absence of trapezius and rhomboids became evident, for 
the contours of the ribs could be seen behind between 
the scapula and the spine. 

Duchenne has rather fully dealt with cases of wasting 
of portions only of the trapezius, and he distinguishes 
between the upper or respiratory portion, the middle or 
elevator portion, and the lower or adducting portion of 
the muscle. He also expresses the opinion that the 
upper part of the muscle will not be completely para- 
lysed unless its nerve from the cervical plexus is dam- 
aged as well as the spinal accessory. 

207. The serratus magnus. — Paralysis of this mus- 
cle is interesting, because the deformity which results 
from it is peculiar. The serratus magnus is supplied by 
the posterior thoracic nerve, which rises from the fifth, 
sixth, and seventh cervical nerves, and runs down the 
side of the chest behind the brachial plexus to reach the 


muscle. The position of the nerve makes it liable to 
injury, especially in the side of the neck, and its inde- 
pendent course explains the reason why paralysis of the 
serratus magnus is frequently seen without any other 
muscle being affected at the same time. Occasionally 
the nerve to the rhomboids comes off as a branch from 
the first part of the nerve to the serratus, and therefore 
the rhomboids may be paralysed with the serratus 
magnus. In the first part of its course the nerve runs 
in the substance of the scalenus medius muscle. 

The peculiar deformity which characterises paralysis 
of the serratus magnus is easily recognised if looked for. 
When the patient is examined with the arms hanging 
down, the shoulder may seem natural, but if the patient 
be told to extend the arms horizontally in front of him, 
the posterior border of the scapula on the affected side 
becomes prominent, projecting like a ridge from the 
level of the back, fig. 76. In a healthy person the 
scapula remains flat and closely applied to the thorax 
during this movement ; the function of the serratus 
magnus is to hold the scapula, and especially its pos- 
terior border, closely to the side of the thorax. When 
the arms are extended in front, the action of the 
deltoid tends at the same time to throw^ the scapula 
backwards, and this is resisted by the simultaneous 
contraction of the serratus magnus. If the deltoid be 
paralysed as well as the serratus, the patient cannot 
extend his arm horizontally, and the deformity due to 
the paralysis of the serratus, cannot be brought out in 
the way just mentioned. In this case, if the shoulder 
be pushed back while the patient is told to resist, it 
may be found that the posterior border of the scapula 
can be more easily displaced on the side of the para- 



Paralysis of the serratus magnus is not uncommon as 
a result of direct injury to the nerve in the side of the 
neck. The following example will serve as an illustra- 
tion of the usual history of such cases: — A man was 
using an iron bar as a lever to move heavy weights 
along the ground, which he did by putting the end of 
the bar on his shoulder, and pushing upwards forcibly 

Fig. 76.— Paralysis of right serratus magni 

against it ; he felt a pain, and soon afterwards he found 
that his shoulder began to "grow out." When he came 
under observation there was marked paralysis of the 
right serratus magnus, and the rhomboids were also 
affected, which made the characteristic deformity of the 
shoulder even more pronounced. 

In two other cases the patients had suffered severe 


injuries, one having been crushed in a Hft accident, in 
which he broke his forearm, and the other having been 
hurt by a heavy packing case, which fell upon him. 
Both of these, in addition to other injuries, had para- 
lysis of one serratus magnus — the right. Indeed, all 
the cases of paralysis of the serratus magnus from in- 
jury which I have seen have been on the right side, and 
in male patients. 

The notion is sometimes entertained that the peculiar 
position of the shoulder-blade described above is due to 
dislocation of the latissimus dorsi from its position at 
the angle of the scapula. This view is erroneous. 

208. The rhomboids.— These are supplied by a 
special nerve, which comes off from the fifth and sixth 
roots. In common with the other muscles, whose 
nerves run a somewhat exposed course in the neck and 
shoulder, the rhomboids are liable to paralysis from 
injury. It is not usual to find them paralysed alone. 
When they are paralysed the posterior border of the 
scapula is less firmly placed than in health, and the 
fingers can be introduced under the edge of the bone 
more easily than usual. If the trapezius be' well deve- 
loped, it is not very easy to make out the paralysis of 
the subjacent rhomboids by electrical testing. 

209. The scapular muscles. — The supra- and infra- 
spinati are often paralysed, as the result of blows upon 
the shoulder, though less frequently than the deltoid. 

When the spinati are wasted, the spine of the scapula 
becomes prominent, and the muscles themselves can be 
seen to be diminished in bulk. The patient is unable 
to perform external rotation of the humerus in a proper 
manner if the infra-spinatus is paralysed ; and the other 
external rotator of the humerus, the teres minor, is often 
affected simultaneously though supplied by a different 


nerve. The movement of external rotation is necessary 
in writing for moving the hand across the page, and in 
sewing the same muscles also come into play. 

The nerve (supra-scapular nerve) which supplies the 
spinati is exposed to the risk of injury, owing to its 
superficial position on the shoulder. The supra-spinatus 
is a less important muscle than the infra-spinatus, and 
its condition is not so easy to determine, because it is 
thickly covered by the trapezius, which makes electrical 
testing of the muscle difficult, and its functions as an 
elevator and a weak internal rotator of the humerus can 
be completely performed by the other muscles. When 
the infra-spinatus is paralj^sed, it is usually extremely 
probable that the supra-spinatus is in the same condi- 

The internal rotators of the humerus, namely, the 
sub-scapularis and teres major, have a nerve supply 
(the sub-scapular nerves), which escapes injury much 
more often than the spinati ; and the same may be said 
of the latissimus dorsi, also supplied by a similar nerve — 
the long sub-scapular. 

These muscles frequently escape, even in very severe 
injuries of the shoulder ; the pectoralis major and minor 
also escape as a rule. Thus I have seen a patient with 
complete paralysis of all the muscles supplied by the 
brachial plexus, except the internal rotators, the latissi- 
mus dorsi, and pectorals, and similar cases are not very 
uncommon, especially after serious dislocations of the 

210. The deltoid. — Paralysis of this muscle from 
blows upon the shoulder or dislocation of the shoulder- 
joint is one of the most common forms of paralysis in 
the upper extremity. 

The circumflex nerve is exposed to injury in its course 



through the muscle, and its trunk may also be strained 
in dislocations, or it may be compressed by a crutch or 
axillary pad. The teres minor suffers with the deltoid 
when the injury is to the trunk of the nerve ; when the 
injury is in the intra-muscular part it may escape. It 

Fig. 77.— Paralysis of right deltoid. 

is not always easy to determine the state of the teres 
minor by electrical testing, as it is so much covered 
by other muscles, nor by observing the voluntary 
movements of the patient, as its functions can be ade- 
quately performed by the infra-spinatus. The attempt 


to ascertain its condition, however, should always be 

The spinati are often paralysed by the injury which 
paralyses the deltoid. 

The flattened appearance of the shoulder, and the 
prominence of the acromial process of the scapula make 
it easy to recognise paralysis of the deltoid, unless the 
subject be very stout. In infants also the adipose tissue 
which covers the shoulder may mask the wasting of the 
muscle. When the wasting and paralysis are extreme 
the head of the humerus is no longer held up in the 
glenoid cavity, but can be seen and felt to hang loosely 
in a state of partial dislocation, and to be freely move- 
able in its socket. One may even be able to push the 
tip of a finger between the acromion and the head of 
the humerus. In cases of paralysis of the deltoid it is 
not uncommon to find some adhesions or creaking in 
the shoulder joint ; for an injury of the circumflex nerve 
may produce paralysis of the muscle and changes in the 
articular surfaces. In examining a patient who com- 
plains of weakness in the shoulder it is useful to bear 
this in mind, and to test the condition of the deltoid, 
for otherwise one may regard the case as one of primary 
arthritis of the joint when the articular mischief is in 
reality secondary to injury or disease of the circumflex 

When the deltoid is paralysed the arm cannot be 
raised to the horizontal position, and the utility of the 
limb is very seriously diminished for a very large num- 
ber of movements, as there is no other muscle able to 
supplement it to any appreciable extent ; the supra- 
spinatus has a similar function to the deltoid, but it is 
too feeble to be able to raise the weight of the arm. It 
sometimes happens that part only of the deltoid is para- 


lysed ; I have notes of three cases. In one the patient 
had had suppuration round the shoulder, and an in- 
cision for the evacuation of the pus was made on the 
posterior aspect of the joint. One of the branches of the 
circumflex nerve was injured, and the posterior half of 
the muscle was wasted, and showed a partial reaction 
of degeneration. Under electrical treatment combined 
with daily rubbing the muscle recovered. 

The deltoid is rather apt to suffer in infantile para- 
lysis of the upper limb, and the chances of its recovery 
in this disease are not good. I have known a paralysis 
of this muscle persist as the remnant of an extensive 
paralysis of the whole upper limb, and in other cases 
have found it most difficult to recognise any new growth 
of muscle-fibres in the deltoid, even after months of 
persevering electrical treatment. This may mean that 
the nucleus of origin of the fibres which supply the del- 
toid is a small circumscribed one, or that the muscle, 
working as it does at great mechanical disadvantage, 
cannot afford the loss even of a portion of its fibres 
without serious impairment of its powers. 

In one of my infantile cases the posterior third of the 
deltoid has grown again under treatment into a fairly 
strong muscular bundle, the rest of the muscle remain- 
ing quite wasted. 

In the ordinary traumatic paralysis of the deltoid the 
prognosis is more favourable. The majority of the 
cases recover, but there is a considerable minority 
which do not, and on this account it is w4se to express 
a guarded opinion when there is much wasting and 
a reaction of degeneration, and the prognosis must be 
made to depend upon the behaviour of the muscle under 
treatment. If the electrical reactions are normal, or 
show only a quantitative change, or the partial reaction 


of degeneration, the prognosis is more favourable. 
Taken generally, the deltoid may be said to be a 
muscle which is easily damaged, and has not a very 
great recuperative power. The presence of articular 
changes in a case of paralysis of the deltoid is very 
common, as both muscle and joint are supplied by the 
circumflex nerve, and both suffer when the nerve is 
injured. Adhesions in the joint should be treated by 
mechanical means after the nerve has recovered its 
functions. If the adhesions are broken down before 
the muscle and nerve are restored they are very likely 
to form afresh. The skin over the deltoid receives 
sensory fibres from the circumflex nerve, and impair- 
ment of sensation or anaesthesia is frequently to be 
found if looked for when the muscle is paralysed. 

211. Combined paralyses of the upper limb. — 
It often happens that many of the muscles of the arm 
are paralysed together from injury or disease of the 
nerve-trunks. Inflammatory processes or syphilitic or 
other new growths may aftect some of the nerve roots 
at their points of exit from the vertebral column in the 
The neck. After a serious dislocation of the shoulder, 
and particularly if this has remained for some hours 
unreduced, there may be complete paralysis of the 
whole limb. Mr. Bowlby has published '••'' several cases 
in which rupture of all the roots of the brachial plexus 
has been caused by violent injuries or dislocations of 
the shoulder. When the roots are torn out of the spinal 
cord there may be laceration of the fibres destined to 
emerge from the thoracic cord to supply the cervical 
sympathetic, and the pupil on the injured side may be 
contracted in consequence. Several cases have been 
reported in which this has been observed. 

* " Injuries and Diseases of Nerves." London, i88g. J. & A. 


Several causes combine to produce extensive para- 
lysis after a dislocation. The head of the humerus 
presses upon the brachial plexus in dislocations forward 
below the coracoid process, and so produces paralysis 
below that point ; but this pressure will not cause para- 
lysis of the muscles of the scapula, for these are sup- 
plied by branches given off higher up, and yet they are 
generally, if not always, implicated. It is said that the 
upper cords of the plexus may be compressed between 
the clavicle and the vertebral column if the violence has 
tended to drive the shoulder backwards, for the shoulder 
has free play from the sterno-clavicular joint, and might 
be driven sufficiently far back to produce such com- 
pression. Also the upper cords of the plexus are 
directly subjected to traction from the injury, or finally 
they may be damaged by the efforts employed in reduc- 
ing the dislocation, and from their position and direction 
they are more likely than the lower roots of the plexus 
to suffer in this way. 

It seems probable that the upper cords of the plexus 
are most likely to be injured by traction, either in the 
injury or in the efforts to reduce the dislocation ; while 
the nerve-trunks of the arm are injured lower down by 
the pressure of the head of the bone against them. The 
subscapular nerves by their position, and by the direc- 
tion in which they run, are rather better protected than 
the other nerves from both these accidents ; and this 
perhaps accounts for the frequent escape of the latis- 
simus dorsi, the subscapularis, and the teres major 
muscles in extensive paralysis of the shoulder and arm 
from injury. These muscles may also escape complete 
paralysis after injury through deriving their nerve 
supply from many separate nerve-roots of the brachial 



212. Erb's paralysis. — One particular type of com- 
T^ined paralysis affecting the muscles of the shoulder 
and arm has received this name, though in France it 
is often known as the Duchenne-Erb type, because 
Duchenne first drew attention to it, and reported five 
examples. It was Erb who, in 1874, pointed out the 
anatomical reasons for the special grouping of the para- 
lysed parts. The affected muscles are the biceps, 
coraco-brachialis, and brachialis anticus, which are 
supplied by the musculo-cutaneous nerve ; the deltoid 
(circumflex nerve), and one muscle supplied by the 
musculo-spiral, namely, the supinator longus ; often 
the spinati too (supra-scapular nerve) are involved. 
The affection of the supinator longus alone among the 
muscles supplied by the musculo-spiral nerve seems 
at first to be a perplexing feature, but it is easily ex- 
plained on the ground that the injury is situated above 
the point at which the musculo-spiral nerve is built up. 
Compare the condition in wrist drop from lead, in which 
the supinator longus may escape when the rest of the 
musculo-spiral area is affected. Erb pointed out that 
an injury limited to the two upper roots of the brachial 
plexus, the fifth and sixth cervical, or their combined 
trunk, would produce the kind of paralysis under con- 
sideration ; and further showed that these cords can 
be directly stimulated at a point in the neck one inch 
above the clavicle and a little external to the outer 
border of the sterno-mastoid. This is known as Erb's 
motor point, and by means of an electrode applied to 
it the muscles in question can be readily thrown into 
simultaneous contraction (§ 131). 

The existence of Erb's paralysis as a clinical unit 
depends upon the comparatively exposed position of 
these two nerve roots, just as we have seen that para- 



lyses of some of the single muscles of the shoulder are 
common for the same reason, and varieties in the extent 
of the paralysis exist according as the injury or disease 
affects chiefly the fifth or the sixth roots or their united 

From the investigations of Ferrier, Herringham 
(§ 132) and others, we have a fair knowledge of the 
levels at which the different components of the nerves 
of the upper limb leave the spinal cord. There is a 
certain amount of variation between individual cases, 
so that we cannot state absolutely that certain fibres 
run always in the fifth root, and certain others only in 
the sixth or seventh. Moreover many, or most of the 
limb muscles, receive their nerve-supply by roots emerg- 
ing at more than one level ; for example, the serratus 
magnus from the fifth, sixth, and seventh cervical 

From what is known one would expect that a lesion 
of the fifth and sixth roots, or of their combined trunk, 
should involve not only the muscles already mentioned, 
but also the rhomboids, the teres minor, the subclavius, 
and the upper parts of the pectoralis major and serratus 
magnus, and the supinator brevis, and most of these 
muscles have been noted as involved in some of the 
recorded cases. When they escape it must be due to 
their extensive representation in the nerve-roots which 
go to make up the brachial plexus. ''"' 

It must be borne in mind that Erb's paralysis is not 
in the least a special form of disease. The name has 
the advantage of brevity alone. Any sort of injury or 
disease which is limited to the upper part of the brachial 
plexus will produce paralysis of the group of shoulder 

* For much important work upon these and associated matters, 
see Sherrington, " The Spinal Animal," Med. Chir. Trans., 1899. 



and arm muscles already mentioned. In particular, 
injury to the child arising during difficult labour is a 
common cause, so that Duchenne described it as "[ob- 
stetrical " palsy of the arm. Among twenty cases of 
which I have notes, seven were caused in this way,'four 

Fig. 78.— Paralysis of trapezius, spinati and deltoid on right side. 

followed direct injury, one was due to sarcoma of the 
cervical vertebrae, though, from extension of the disease, 
the paralysis was not long limited to the muscles of the 
Duchenne-Erb group. One was associated with an 
abscess in, the neck, and the remainder came on gradu- 
ally and were due to neuritis of some kind. 

CO 2 


All degrees of combined paralysis from the typical 
Duchenne-Erb type to complete paralysis of the shoulder 
and arm may be met with. 

The triceps in some cases and the extensors of the 
wrist in others, have been noted to be weak in cases of 
Erb's paralysis. In two cases I have noted some weak- 
ness of the upper part of the pectoralis major. 

Infantile paralysis may sometimes resemble Erb's 
paralysis in its distribution, but it is not likely often to 
be confounded with it if the history of the case and the 
distribution of the paralysis be carefully taken into ac- 
count. Fig. 77 is from a case of infantile paralysis, and 
show^s wasting of the deltoid, spinati, and trapezius, the 
last only in its upper part. 

213. The nerve-trunks of the arm and fore- 
arm. — The musculo-spiral, the median and the ulnar 
nerves are often injured in their course in the arm and 
forearm. The usual causes are pressure, including 
pressure from bandages or splints too tightly applied, 
incised wounds, implication in callus or scar tissue, and 
contusions. Pressure palsies affect more especially the 
musculo-spiral in the upper arm ; while the ulnar and 
median suffer more particularly from incised wounds, 
and in the forearm. In all cases the first thing to do is 
to test to determine the situation of the lesion, its 
severity and above all, to ascertain whether the nerve 
is likely to be severed or not. If it is severed treatment 
by electricity is useless until it has been sutured (see 
§ 140). Paralysis from the pressure of splints and 
bandages is sufficiently common to be of importance, 
and though fortunately it is not usual for injury pro- 
duced in this way to cause permanent harm, yet some- 
times it does do so. I have notes of a case in which 
the ulnar muscles were almost totally atrophied as the 


result of bandaging, and I have seen quite a consider- 
able number of cases in which there was little or no 
doubt that the bandaging had been the cause of para- 
lysis. Thus in one patient who received an incised 
wound involving the median and ulnar trunks it was 
found, when the wound had healed, that he had deve- 
loped a paralysis of the musculo-spiral as well. I have 
little doubt that many of the cases of so-called "reflex 
paralysis " have been due to injuries from splints and 
bandages. Paralysis from tight bandaging is seen with 
especial frequency among persons who have received 
injuries when far away from skilled assistance, and 
have been bound up tightly and left so until medical 
assistance could be reached. 

In all cases of injury to nerves, except when the 
nerve is severed, electricity is by far the best mode of 
treatment. Arm-bath methods are of great convenience 
for injuries at or below the elbow, but good results are 
also obtained by direct applications. The coil or sinu- 
soidal current may always be used, and in cases with 
RD it may be supplemented by the battery current 
applied in a labile manner. 

214. The musculo-spiral nerve. — Paralysis of the 
muscles supplied by this nerve is characterised by the 
presence of wrist-drop ; usually the extensors of the 
wrist and fingers and the supinator longus and brevis 
are involved ; the triceps may either escape or may be 
involved according as the injury is high up in the arm 
or not. 

Musculo-spiral paralysis from pressure on the trunk 
of the nerve during sleep is extremely common, at least 
among hospital patients. 

The usual history is that the patient having had too 
much to drink goes off into a heavy sleep, from which 


he awakes with his hand and forearm powerless. Often 
the patient has slept while sitting at a table with the 
head resting on the arm, or with the arm hanging over 
the back of a chair ; in either case the musculo-spiral 
nerve trunk has been pressed upon. Almost always the 
patient has been under the influence of alcohol and has 
slept very soundly. Otherwise the discomfort felt in 
the arm would have been likely to awake him before 
the production of more than a transient paralysis. 
Almost all the cases are in intemperate persons. The 
predisposing effect of intemperance is well shown in the 
following case : — A potman after sleeping for two or 
three hours developed a pressure palsy of his left 
musculo-spiral nerve. This got better, but in the fol- 
lowing year he injured his ankle and was obliged to 
use a crutch. This brought on another attack of 
musculo-spiral palsy before he had used the crutch 
more than ten days. 

Slight degrees of temporary paralysis from pressure 
on a nerve-trunk during sleep are familiar to most 
persons. To notice a numbness or a feeling of pins and 
needles in one arm on awakening from sleep is not 
uncommon, especially among those Avho are not in 
vigorous health. 

Pressure paralysis has been thought to be secondary 
to compression of the blood-vessels of the limb, produc- 
ing anaemia of the nerve, but if this were the case the 
paralysis should not be confined to the region of one 
particular nerve-trunk, as is the rule. It would rather 
be expected to involve chiefly the distal parts, irrespec- 
tive of the nerve supply if it were due simply to anaemia 
of the limb from compression of the main artery. 

A case which came under my observation some years 
ago of a pressure palsy in the leg shows that it is the 


nerve itself which suffers from compression. In that 
case the pressure was on the great sciatic nerve at the 
back of the thigh, and there could not have been any 
compression of the femoral artery. The patient was 
a young man who attended a meeting, and in order to 
have a better view of the proceedings he sat for an hour 
upon the back rail of his chair ; at the close of the 
meeting he found his leg numb and helpless, and was 
assisted home. Two days later he came under obser- 
vation. He had paralysis of all the muscles below the 
knee. He recovered in a fortnight under treatment by 
rubbing and the induction coil current. 

Sleep palsies are almost always limited to the mus- 
culo-spiral nerve. 

In crutch palsy too it is usually the musculo-spiral 
nerve alone which is paralysed, but the circumflex 
nerve, or the ulnar or median may also be involved. 
Sleep palsies are always unilateral ; crutch palsies may 
be double if two crutches are used, they are usually 
more marked on the side of the injuredfleg. 

The degree of impairment of sensation varies much ; 
as a rule there is some complaint of numbness on the 
back of the forearm and hand, and some anaesthesia 
may be detected. 

Pressure palsies vary considerably in severity. Those 
in w^hich the electrical reactions are not much impaired 
may recover in ten days or a fortnight. When the 
reaction of degeneration is present the duration will be 
longer. Recovery can be confidently expected in un- 
complicated cases, where the pressure has not lasted 
very long, and it is certainly promoted by electrical 
treatment. I have often seen improvement start at 
once on the commencement of electrical treatment, 
after weeks had been wasted in vain in the expectation 


of spontaneous recovery. It is probable, however, that 
even in these the paralysis would go away of itself in 
time, but this does not prove that electrical treatment 
is unnecessary. 

When the pressure is due to the use of crutches they 
must either be given up, or if that is impossible the 
head of the crutch must be well padded, and the state 
of affairs must be explained to the patient so that he 
may be able to co-operate; crutches with handles w^hich 
can be grasped in the hands are the best, for with them 
the patient can transfer part of his weight from the arm- 
pits to the wrists. 

The other common affection of the musculo-spiral 
nerve, namely, lead poisoning, has been dealt with in a 
preceding paragraph. Implication of the nerve in 
callus after fracture of the humerus is not very rare and 
may require a surgical operation to liberate it. The 
nerve may also be wounded by the fragments of the 
bone in cases of fracture. 

215. The ulnar and median nerves.— These nerves 
are frequently divided at or near the wrist by incised 
wounds ; a very large number of the cases being from 
cuts caused by broken glass. It is not uncommon for 
both nerves to be divided in one accident, and if the 
ends are not re-united when the wound is first dressed, 
wasting and paralysis of the intrinsic muscles of the 
hand is the result. 

When the ulnar nerve has been completely divided 
near the wrist the symptoms produced are : — i. Paraly- 
sis with wasting and the reaction of degeneration in the 
hypothenar eminence, in all the interossei, in the two 
ulnar lumbricales, and the adductor and flexor brevis 
(inner head) of the thumb. After a time the deformity 
known as the " clawed hand " is produced. The palm 


becomes thin and flat, the heads of the metacarpal 
bones become unduly prominent, the proximal phalanges 
are over-extended, the distal phalanges are permanently 
flexed. This is the result of the paralysis of the inter- 
ossei. It has already been shown (§ 190) that in the 
foot the action of the long flexors of the toes is to flex 
the distal phalanges only, and that of the long extensors 
is to extend the proximal phalanges, and that when the 
interossei are paralysed the clawed attitude of the toes 
is produced in consequence. The mechanism is the 
same in the case of the hand, the interossei flex the 
proximal phalanges and extend the distal ones ; and so 
supplement the movements of the fingers which are per- 
formed by the long flexors and extensors. 2. There is 
loss of sensation in the little finger, in the ulnar half of 
the ring finger both front and back, and in the corre- 
sponding part of the palm and the dorsum of the hand. 
3. Trophic changes are sometimes produced in the skin 
and finger nails of the anaesthetic area, often with 
cedema ; the temperature of the part is lowered, and 
sometimes there is very severe pain of a burning cha- 
racter, to which the name of " causalgia " has been 
given, this is not very common, nor is it usually present 
when the nerve has been completely divided. When it 
exists the temperature is raised above that of the oppo- 
site side, and the patient experiences a sensation of 
heat and seeks for relief by cold applications. These 
trophic changes signify an irritative lesion, and are not 
found from simple division of the nerve-trunk. 

After division of the median nerve at the wrist the 
conditions are different, the clawed hand which is so 
characteristic of the divided ulnar nerve is not present, 
and the chief feature is the wasting of the thenar emin- 
ence, and the averted or ape-like thumb, which lies 


with the nail facing dorsally ; the abductor, opponens 
and outer head of the flexor brevis of the thumb are 
paralysed, atrophied, and show the reaction of degenera- 
tion. There is loss of sensation in the thumb, index, 
middle, and half the ring fingers, and in the correspond- 
ing part of the palm, and of the two distal phalanges of 
the same fingers on the dorsum of the hand. 

216. The lower limb. — Paralysis from injury is 
much less common in the leg than in the arm. I have 
notes of only a few instances. In one recorded case 
there was paralysis of the front leg muscles from the 
pressure of a leather pad upon the peroneal nerve just 
below the head of the fibula. The patient was a man 
who walked daily upon stilts which were strapped to 
the legs, and so set up the pressure upon the nerve. 
Another case is referred to in § 214. 

Other cases have followed injury about the knee-joint, 
or a fracture through the lower third of the femur, and 
one was after an operation for the relief of genu valgum. 
The most usual seat of the injury to the nerve-trunks of 
the lower extremity is in the external popliteal nerve or 
the peroneal nerve. This was the case in two instances 
which have come under my notice. The pressure oc- 
curred during work. In one, a carpenter sat on the 
ground with one leg doubled under him, in the other, 
a leather sewer fixed her work against the under side 
of a table, holding it there by the upward pressure of 
the left knee against the outer side of the right knee 
which was crossed over the left one. In both cases 
there was pressure upon the peroneal nerve. 

217. Muscular atrophies. — Prolonged treatment 
by the sinusoidal bath method has been applied to 
several cases of the shoulder and upper arm type 
(Landouzy-Dejerine) of muscular atrophy in the elec- 


trical department at St. Bartholomew's Hospital with- 
out any decided result. The most that could be said 
of the cases was that there seemed to be some retarda- 
tion of the advance of the muscular atrophy while treat- 
ment was in progress. In other cases with the peroneal 
type (Charcot-Marie) of muscular atrophy the results 
have been equally unfavourable. 

218. Pes cavus. — This has already been noticed 
under the heading of infantile paralysis. It is often 
present in diseases which lead to muscular atrophy, and 
then signifies a paralysis of the interosseal muscles. 
But in many cases of pes cavus the electrical reactions 
of the interossei are not altered and the deformity is 
due to spasm of the long flexors and long extensors 
rather than to weakness of the intrinsics of the foot. 
Cases of this kind are not uncommon and are seen in 
young adults, with a history of gradual onset. Both 
sides are involved. The knee jerks are excessive and 
the leg muscles are large and firm, the interossei give 
normal reactions in these cases which are clearly spinal 
in character and correspond best to the descriptions 
of primary lateral sclerosis. In these cases electrical 
applications do no good but rather the opposite. 

219. Neuralgia. Painful neuritis. — The word 
neuralgia is applied to many different conditions in 
in which pain is felt in the course or area of distribu- 
tion of a nerve, and the term has been defined as pain 
in the region of a nerve unconnected with inflammation 
or other morbid state in the nerve to which the pain is 
referred. There is no doubt that a neuralgic pain in 
one part may be set up in a reflex way by irritation 
acting upon some more or less remote part. Fagge has 
given as an instance the trigeminal neuralgia so often 
excited by disease of a tooth, and severe supra-orbital 


pain may be instantly produced in some persons by 
the eating of an ice. Neuralgia of the testis from 
renal calculus is another familiar instance of reflex 

When we compare sensory with motor nerves we 
find an analogy between anaesthesia and paralysis, and 
also between neuralgia and muscular spasm. The two 
latter are especially associated with irritation, direct or 
reflex, of sensory or motor nerves or nerve centres. And 
we may also learn from the comparison of motor and 
sensory phenomena that just as in the case of paralysis 
the lesion producing it may be in the motor fibres or the 
ganglion cells, or in the motor tracts of the spinal cord 
or brain, so too in the case of sensory disturbances the 
lesion producing them may occupy any part of the sen- 
sory tract, peripheral or central, and it is therefore 
necessary before arriving at any final opinion as to the 
cause of a neuralgic pain, to explore all those parts so 
far as is possible. It is folly to regard them all as 
' neuralgia " and then blindly to apply remedies for 
neuralgia with hopes of cure when the trouble may be 
due to any one of a number of causes, some curable 
others not curable. 

It is useful to distinguish betw^een pains referred to 
the area of distribution of a sensory nerve and pains 
felt in the course of the nerve-trunk. The former are 
more particularly associated with the sensory fibres 
proper, and the latter with the nervi nervorum which 
supply the perineurium of the nerve-trunks with sensi- 
bility. It is of especial importance to examine care- 
fully, in all cases of neuralgic pain, for the possible 
existence of pressure or deep seated inflammation as a 
cause of the pain. Thus a brachial neuralgia may be 
due to gumma or other new growth of the cervical 


vertebrae, and sciatica to inflammatory processes in the 

The electrical treatment of neuralgia may take either 
of two different directions. In the more rational one 
the action of the constant current is brought to bear 
upon the seat of pain in the hope that its sedative 
effects may gradually produce a permanent impression 
upon the nerve. In the other the principle of counter- 
irritation is followed, and by the production of painful 
cutaneous impressions it is sought to create a diversion, 
as it were, in the nature of the impulses conducted 
along the nerve, and so by influencing the centres to 
remove the neuralgic condition. Counter-irritation is 
a very popular treatment for neuralgic pains, and elec- 
tricity affords a counter-irritant of great convenience in 
application. Electrical counter-irritation has the great 
advantage that it does not damage or destroy the skin 
in the way that blisters or the cautery do. The treat- 
ment by counter-irritation is the cruder method of the 
two, and may do harm instead of good. 

When painful points are present in a case of neuralgia 
the electrode should be applied to them. These pain- 
ful points correspond to spots at which the cutaneous 
nerves emerge from bony canals or fasciae, but perhaps 
they merely signify a general tenderness of the nerve- 
trunk, which is most manifested at those particular 
places where they are most subject to pressure. 

220. Facial neuralgia. — The fifth nerve is one of 
the commonest seats of neuralgia, and in very many 
cases its condition is one of " reflex neuralgia," the 
teeth in particular being very commonly at fault, while 
errors of refraction should also be looked for. But not 
all cases of trigeminal neuralgia can be traced to an 
exciting cause, and the most severe form, known as tic 


dotdoureux, is often present when no source of irritation 
can be found. The beUef that this form of neuralgia is 
of central origin has much in its favour. Duchenne's 
treatment for all forms of neuralgia (except those in 
which some gross lesion of the nerve was present) con- 
sisted in severe induction coil applications to the pain- 
ful area, using a coil of many turns with the wire brush 
after drying and powdering the skin to diminish its 
power of conduction. If the skin were not first dried 
the current penetrating the tissues to the trunk of the 
nerve w^as likely to do harm instead of good. He re- 
ports one or tw^o cases of severe trigeminal neuralgia 
which derived benefit from this mode of cutaneous 
counter-irritation, but confesses that his successes were 
rare. Statical treatment by the brush discharge 
(§ 102) will sometimes effect a cure. Daily applications 
have been advised, and in very acute attacks two or 
three applications may be made in one day. Tic dou- 
loureux will sometimes disappear by simple positive 

The stabile action of the anode to the painful part is 
often of use in trigeminal neuralgia, and this is the 
method which should be employed in the first instance. 
It is remarkable to see how a recent neuralgic pain will 
sometimes fade away quickly under this treatment. 
Old standing neuralgias are much less easily got rid of, 
but the same mode of treatment should be applied and 
persevered in, Bergonie (Arch, d'elect. medicale, Oct., 1897) 
has reported the successful treatment of old standing tic 
douloureux by means of the battery current with large 
pads to cover the whole side of the face, and large cur- 
rents. Six cases are given, and a figure of the large 
pads to be used. The paper is followed by others 
giving the experiences of Guilloz, Bordier, and 


Debedat on the same subject (see also same Journal, 
June, 1898). 

221. Cervical neuralgia. — In a patient, a young 
married women, who had had herpes of the descending 
branches of the cervical plexus, a persistent neuralgic 
state of those nerves was left which caused much suf- 
fering, and a good deal of anxiety because its nature 
was not understood. After it had lasted without im- 
provement for nearly two years she came under electri- 
cal treatment, and was completely relieved within a 
fortnight. The localisation of the pain in the nerve- 
trunks and in their peripheral branches was clear in 
this case, and applications of the anode were used. 
There has been no return of the pain since. 

222= Brachial neuralgia. — Neuralgia affecting the 
upper arm is not uncommon, and great relief may be 
given by electrical applications. We may distinguish 
between deltoid rheumatism which is a neuritis of the 
circumflex nerve, and a more extensive neuralgic con- 
dition of the shoulder, which extends into the arm and 
sometimes into the forearm and hand, and is probably, 
in most cases due to a neuritis involving a greater or 
lesser part of the brachial plexus. The pain may be 
very severe with exacerbations at times. One severe 
case in my experience was so bad that the patient could 
not sleep at night, and a touch in the axilla was enough 
to induce violent shooting pains which were felt down 
into the fingers. When the case came under treatment it 
had already lasted several wrecks in spite of all kinds of 
drug treatment, relief followed quickly upon labile applica- 
tions of the battery current. Gout, rheumatism, syphilis 
may be the predisposing causes and should be enquired 
for and treated. The battery current carefully applied, 
labile, without interruptions, gives great relief, and if 


persevered in will cause the complete disappearance 
of the trouble. The active electrode must be applied 
over the seats of most pain, the indifferent electrode to 
the cervical spine. In some cases of brachial neuralgia 
of old standing the effect of electrical applications is 
rapid and complete. A lady who had consulted many 
physicians without relief was referred to me for electri- 
cal treatment some time ago and was treated with sinu- 
soidal baths. She at once began to improve, and 
within a fortnight was completely and permanently 
freed from her pains. The cases in which an immediate 
cure follows electrical applications are perhaps those 
in which neuralgia persists as a habit after the disap- 
pearance of the lesion in the nerve which originally 
started the neuralgia. I have notes of rapid good re- 
sults in brachial neuralgias after various kinds of elec- 
trical applications, namely the direct battery current 
applied locally, the sinusoidal arm-bath or general bath, 
and the statical breeze. 

The cases due to neuritis which occur in the gouty or 
rheumatic and those complicated by the presence of the 
climacteric period (§ 203) though more slow to dis- 
appear, are nevertheless extremely favourable cases for 
electrical treatment. As has been mentioned already 
one must always examine one's cases most carefully 
for possible new growth, inflammatory or other, or for 
conditions leading to pressure upon nerve-trunks before 
undertaking the relief of neuralgic pains by electrical 
applications. Neuralgia following herpes is well known 
to be more obstinate in elderly patients than in those 
who are young. 

223. Sciatica. — Sciatica varies much in severity, 
and in duration. It is now generally recognised that 
electrical treatment is useful for its relief, although from 


time to time cases are met with where sciatica persists 
for a long time in spite of treatment, yet as a rule they 
do very well. The battery current is the best applica- 
tion in recent and acute cases, but general electrifica- 
tion with the bath, using the induction coil or better 
still the sinusoidal current from the mains, answers well 
in many of the cases. 

Steavenson''' has published an account of sixty cases 
of sciatica treated by electrical applications ; of this 
number thirty-seven were cured, eleven were improved, 
two failed, and the remainder were uncertain. The 
method employed was to apply the kathode labile to 
the back of the thigh along the course of the sciatic 
nerve, and over the lower portion of the spine, while the 
anode was placed on the abdomen. The anode may 
also be placed on the lumbar spine. Each application 
lasted for eight to ten minutes, and the integument over 
which the' electrode has passed becomes suffused with a 
bright blush, the patient experiencing a glowing feeling 
of warmth in the same tract. The stiffness of the 
muscles is also relieved, and the patient is able to bend 
down and get up from a sitting position with great ease 
for several hours, even after the early applications. In 
the electrical treatment of neuralgic pains large elec- 
trodes and large currents should be used. Prognosis is 
good if the first treatment produce even a temporary 
relief from the pain. 

Counter irritation by means of the wire brush, using 
the long secondary coil after drying the skin and pow- 
dering it with starch powder, is sometimes efficacious 
in old cases of sciatica, as in other forms of neuralgic 
pain; the battery current, however, is a much better 
treatment in bad cases. Descending currents stabile, 
* Lancet, Jan., 1884, and July, 1886. 



with a few interruptions (not reversals) to close the 
sitting are preferred by Remak, and most later authors. 
My own practice is to begin with the battery current, 
following Dr. Steavenson's rules, and after a time, when 
the severity of the pain is subsiding, to employ the 
electric bath with sinusoidal current. This mode of 
application is useful as soon as the patient finds it com- 
forting, and until this is the case the battery current 
must be used in preference. Old standing cases of a 
subacute character may be treated by the sinusoidal 
current immediately. 

224. Other forms of neuralgia. — Painful affec- 
tions of other nerves, for example the anterior crural 
nerve, are sometimes met with, and may be tieated in 
an analogous manner. Relief almost always follows, 
though it may be slow in coming. Electrical applica- 
tions should never be neglected in cases of neuralgic 
pain, for they are far superior to the treatment by drugs 
and irritant applications which have been in vogue for 
so long a time. 

Steavenson and others have described a neuralgic 
state of the pudic nerve."' The affection is associated 
with severe pains in the perineum, often periodic, and 
increased by walking ; it is sometimes accompanied by 
a painful spasm of the urethra whenever an attempt is 
made to pass water. The pain sometimes extends be- 
yond the perineum into the groin. The constant cur- 
rent applied locally will generally relieve the pain after 
a few applications. 

225. Anaesthesia. — The treatment of anaesthesia is 
similar to that used for paralysis (§ 189). The cerebral 
anaesthesia which sometimes occurs with hemiplegia is 
usually not permanent, and it may very often be made 

* Lancet, 1886, vol. ii., p. iSi. 



to disappear by a few applications of the wire brush to 
the affected areas. Hysterical anaesthesia may also be 
dispelled in the same way as a rule. 

When paralysis and anaesthesia coexist from disease 
of the spinal cord or spinal nerves, the prognosis and 
the treatment are similar for both. Very often the 
anaesthesia is much less marked than the paralysis, and 
it recovers more quickly in the favourable cases. 

Anaesthesia of the sensory portions of the trigeminus 
has also been observed. Fagge quotes from Romberg 
a case which came on after exposure to cold and might 
therefore be of a similar nature to the cases of facial 
paralysis produced in the same way. Serious disease 
in the neighbourhood of the Gasserian ganglion may 
also produce anaesthesia of the face. 

226. Optic neuritis and atrophy. — The battery 
current has been used for optic atrophy and optic 
neuritis, and several cases have been reported in which 
improvement of sight has followed. When atrophy 
comes on without previous optic neuritis, the prospects 
are considered less favourable. The treatment is (i) 
transverse currents through the temples with reversals ; 
(2) longitudinal currents through the head, with the 
anode over the closed eyelids. 

The prospects of improvement depend much upon the 
nature of the disease ; when this is of a progressive 
kind, as m tabetic atrophy, good results can hardly be 
looked for. Capriati''' recommends a trial, however, 
and considers that he has obtained improvement with 
battery currents of two milliamperes applied longitudin- 
ally to the skull. His views have been summarised as 
follows : — Electrical treatment is indicated in tabetic 

* Riforma medica, October, 1893. Abstract in Weekly Epitome 
of British Medical Journal. 

DD 2 


atrophy of the optic nerve, in cases in which the dis- 
ease is not running a very rapid course, and before it 
has reached a very advanced stage. If employed in 
the early stages it appears to do good, and arrests, 
with certain limitations, the morbid process, apparently 
by acting on the nerve fibres still unaffected. Better 
results may be anticipated from the application of the 
current antero-posteriorly than transversely, although 
neither method has yielded results warranting great 
enthusiasm. In neuritis affecting the nerves of special 
sense we usually have to deal with a progressive and 
degenerative state and on this account treatment cannot 
give results like those which may be expected to follow 
simple traumatic lesions of the ordinary mixed nerves. 

227. Auditory nerve deafness.— The treatment of 
nerve deafness by electricity sometimes gives good 
results. The method best suited is with the bifurcated 
electrode (fig. 69) and the battery current, using the 
negative pole and interruptions. The current should 
be turned on and off gradually, and should not exceed 
ten milliamperes, and should be reduced to five before 
making the interruptions. Even with this strength the 
patient must be watched for signs of faintness, as syn- 
cope may even be produced. Sittings of six to eight 
minutes, with ten to twenty interrruptions, are best. 
Under this treatment many patients will have the 
hearing improved, I have seen a remarkable increase 
of hearing power follow even the first applications, and 
the effect may be permanently good. The causes of 
nervous deafness of course are numerous, and the cases 
should be chosen ; only those which from their history 
and the results of electrical testing appear to be favour- 
able should be undertaken. The best results follow on 
prolonged courses of daily treatment, and intelligent 


patients can be taught how to carry out treatment for 
themselves and should be encouraged to persevere for 
one or two months. 

228. Tinnitus aurium. — Subjective noises in the 
ears can sometimes be dispelled by the battery current. 
From what has been already said in § 145, it appears 
that when the tinnitus is associated with an irritable 
state of the auditory nerve, good results may be ex- 
pected from the sedative action of the anode, which 
may be applied by a small electrode to the skin imme- 
diately in front of the tragus. I have treated a very 
large number of patients for this symptom, using as the 
active electrode (anode) the instrument figured on page 
259, which is applied in front of the tragus (or on the 
mastoid processes) of both ears at once. The parts in 
contact with the skin should not be of less diameter 
than two -centimetres. If the surface of the electrode is 
too small some soreness of the skin may be produced at 
the points of contact. A pad of moist absorbent wool 
should be placed between the electrode and the skin. 
The indifferent electrode is placed at the back of the 
neck, where it is kept in position by the pressure of the 
clothing ; and a galvanometer and a rheostat (fig. 48) 
should be included in the circuit to enable the operator 
to introduce or remove a resistance of 10,000 ohms 
quite gradually. When everything is ready the current 
is slowly and steadily raised by the current collector to 
five milliamperes (the rheostat being at zero) and 
allowed to pass for ten minutes. As the resistance of 
the skin diminishes the current will increase slowly, the 
galvanometer may be allowed to indicate eight or ten 
milliamperes, each ear is then receiving half that cur- 
rent. If the current should be inclined to rise higher 
the rheostat must be brought into use to keep it at that 


Strength. The patient should be instructed to pay 
attention to the noises and to give notice of any change 
occurring in them in the course of the sitting. The 
effect of the appHcation of the anode to the ears is to 
diminish the noises, while that of the kathode is to 
increase them. The reverse sometimes happens, how- 
ever, and therefore the patient must be tested to find 
out whether the current modifies the sounds. If it 
does so the prospects of improvement are good, and the 
patient should be encouraged to persevere. If neither 
anode nor kathode alter the sounds, the prognosis is 
unfavourable, and it is hardly worth while to continue 
the treatment. In favourable cases the noises will 
diminish during the passage of the current ; if the 
current be too quickly reduced at the end of the treat- 
ment the noises may return as loudly as before, but if 
it be reduced very slowly and gradually this does not 
happen. On this account the rheostat is an important 
part of the apparatus ; at the end of the sitting the 
current is to be reduced by the rheostat first and after- 
wards by the collector. If it happens that the tinnitus 
is dispelled by the treatment, at first the relief is quite 
temporary and the noises will probably return within 
an hour, but after each sitting the period of quiet is 
longer until finally they disappear altogether. If the 
sittings are repeated daily for the first week much time 
will be gained, afterwards it will be sufficient to apply 
the treatment twice a week for a fortnight or three 
weeks, or a month, according to the progress of the 

Tinnitus complicates nearly all the different forms of 
ear disease, for instance it may depend upon the accu- 
mulation of wax, or it may be due to some other tem- 
porary disorder of the ear, which can easily be cured 


by proper local treatment, or it may occur in patients 
whose auditory apparatus is normal, as a part of some 
general morbid condition. 

More commonly, however, some chronic ear mischief 
exists and the removal of the subjective noises may be 
a matter of great interest to the patient, even apart from 
his deafness or other troubles. 

Electrical treatment is able to do a very great deal 
for some cases provided it be properly managed. 

It has been objected to the electrical treatment that 
it is difficult and that the results are uncertain and 
temporary, but there is no doubt whatever that in a 
fair proportion of cases some relief follows, while some 
patients are quite freed from their tinnitus and deafness. 
It is not impossible that the treatment has an effect 
upon the sclerotic change itself (see §§ 229, 230) and 
in additipn it certainly has an effect upon the auditory 
nerve fibres tending to improve their nutrition. But 
unhappily in many instances of tinnitus aurium and 
deafness we have to deal with a progressive degenera- 
tive disease and we do not know how to apply elec- 
tricity to arrest this tendency. 

4o8 MEDICAL i:i.i:c iKici rv. 

CHAPTinv Xlll. 

Othhk Conditions rkodirinc. Electrical Treatment. 

The relief of congestion. Joint atVections. Inilanimatoiy exuda- 
tions. Ascites. Corneal opacities. The urinary ori:;ans. 
Nocturnal incontinence. Constipation. Sexual disorders. 
Cutaneous affections. Galactagogue effects. Guinea worm. 
Suspended animation. Electricity as a test of death. 

2 2g. Joint affections. — The intluonco of electrical 
applications in relieving joint alYections was investigated 
by Remak*-"* so long ago as 1856. As has been already 
observed, the special study of the uses of electricity for 
paralytic atrections has tended to divert attention from 
many of its other applications, among which its uses in 
the relief of congestion and in promoting absorption 
occupy an important place. Remak's cases are so well 
described as to leave no doubt that in his hands much 
beneiit was afforded both in acute and chronic joint 
affections. He employed the continuous current ex- 
clusively, and, so far as one can judge, currents of 
fairly large magnitude. Among the cases which he has 
reported are several of sprains and injuries of joints, 
and of chronic arthritis of rheumatic and other kinds. 

As an example of the effect of the battery current in 
relieving severe congestion, the following case, reported 
by Remak, seems to be worthy of being reproduced in 

A washer-woman, aged 36, fell from a table and felt 
her right foot to be twisted outwards ; so much pain 
* " Galvanotherapie." R. Kemak, 1S60. 


was produced that she could not walk. During the rest 
of the day and through the night she applied cold water 
dressings. The following day she consulted Rernak ; 
she was obliged to drive to his house, and ascended the 
stairs with great pain and difficulty. He found the 
dorsum of the foot much swelled, livid and very tender ; 
the diagnosis made was laceration of some of the tarsal 
ligaments, and extravasation of blood. The aspect of 
the foot was such as to lead to the apprehension that 
gangrene might result. At the patient's urgent request 
electrical treatment was applied. Owing to the thick- 
ness of the skin of the sole of her foot it was necessary 
to use a large number of cells in order to produce any 
'.^msation or reddening of the skin. By repeatedly 
changing the place of application of the electrodes he 
continued the application for twenty -five minutes. 
During this time the livid colouration disappeared, the 
rfidtma. and the pain diminished considerably, and the 
patient could rest her heel upon the ground better than 
before. The warmth of the foot, increased by the 
current, continued until the evening, by which time 
a decided improvement was established, and she passed 
a good night without pain. Next day the colour of the 
foot was normal, and the symptoms were less severe ; 
the treatment was repeated on this and on the next 
three days. She was then so much better as to walk 
v/ithout lam.eness, and in a fortnight was practically 
well. The mode of application is not clearly stated but 
it appears probable that the positive pole was applied 
chiefly to the sole of the foot, but also to the dorsum, 
while the negative was on some indifferent part higher 
up the limb or on the trunk. The view taken by 
Remak in this and in similar cases which he reports is 
that the current produces a marked increase in the rate 


of circulation through the part treated, by a general 
dilatation of its blood-vessels, and as a consequence of 
the improvement in the circulation the products of 
effusion are much more rapidly carried off than would 
otherwise be the case. This view is reasonable, and is 
perhaps the only one which is capable of explaining 
the rapidity of the cure. 

There is no doubt that the constant current may be 
regarded as having a special power of improving the 
circulation in a part and as being useful in this way in 
promoting the removal of cedema and products of 
inflammation, and generally for the treatment of all 
injuries of joints. 

With chronic joint pains of rheumatic origin the 
local application of the battery current, by means of 
large pads, proved equally useful in Remak's hands. 
His best results were in patients who continued to have 
stiff and painful joints after the rheumatic fever had 
left them. 

He quotes a case where there had been rheumatic 
fever ; the patient was ill for seven weeks in his own 
house and for ten weeks in hospital. When discharged 
he was thin and pale, his joints were stiff, especially the 
knee and ankle joints, round which there was thicken- 
ing. He was then treated by continuous currents 
applied to the several affected joints, and after six days 
of treatment was much more free from pain, had more 
power, and the thickenings had nearly disappeared. 

Muscular spasm round an inflamed joint is also 
relieved by applications of the anode. 

In those cases of chronic joint affections which I have 
had the opportunity of treating relief has commonly 
been afforded, sometimes after a brief course of treat- 
ment. Chronic rheumatic joint pains Avill often yield 


in a most remarkable manner to electrical applications, 
even when they have proved most obstinate to other 
forms of treatment. The best method of applying 
electricity is by local applications of the negative pole. 

In gouty arthritis electrical treatment will hasten the 
recovery when the acute paroxysm is over. In the case 
of a hand or foot the part may be immersed in warm 
water to form a local bath, as described in detail in 
§ 167, which see. 

Among recent writings on the subject of the value of 
electricity in the treatment of stiffened joints, a paper 
of Professor Leduc {Arch, d'electricite medicale, 1894, 
p. 478) is to be noted, for it gives us the evidence of 
an exact scientific observer. He describes the case of 
a young lady who developed phlebitis after typhoid 
fever. Following upon this there was a stiffening of 
the left knee joint which was treated unsuccessfully in 
various ways for more than a year. When seen by 
Dr. Leduc the joint was ankylosed, immobile, and 
painful ; it felt cold to the touch, and the tissues sur- 
rounding the joint were thickened and slightly oedema- 
tous. She could not w^alk nor bear with any weight on 
the limb. Electrical treatment was commenced. A 
large electrode (negative) was moulded to fit the region 
of the joint, the positive indifferent electrode being 
applied to the epigastrium, and a current of twenty 
milliamperes was applied for ten minutes. Afterwards 
thirty and forty-five milliamperes for fifteen minutes 
were employed. Improvement quickly began and after 
twenty-two applications extending over two months the 
joint had become freely movable and the patient could 
stand and walk. 

Other cases of the same kind are referred to and the 
writer concludes by saying that the useful action of 


electricity in cases of joints stiffened by past inflamma- 
tion is incontestable. A point of importance for success 
is that the treatment must only be applied to joints 
which are no longer the seat of inflammation. It is 
necessary to wait until all active mischief in the joint 
has subsided. 

In another paper kindly sent to me by Professor 
Leduc and reprinted from the Gazette Medicate de Nantes, 
January, 1893, seven cases are reported which afford 
valuable evidence of the advantages to be derived from 
applications of electricity to joints stiffened by old 
injury or past inflammation. One, a rheumatic case, 
in a gentleman aged 47 was such that for two years the 
patient had to be dressed and carried from his bed to 
his couch by attendants. He could not stand up. 
After thirty applications of the battery current during 
sixty days he could walk well enough to undertake a 
a journey to Paris, and his improved condition was well 
maintained. In a conversation with Professor Leduc 
in 1899 he told me that he still found the treatment of 
stifl"ened joints by the battery current to be one of the 
most satisfactory things in the whole field of medical 
electricity. He considers the negative pole to be 
the most effective for the purpose. Large electrodes 
moulded to fit the surface of the joint are to be used. 
The current may be very conveniently applied through 
the medium of a monopolar or other arm bath when the 
affected joint is either the wrist, the ankle, or the elbow. 

230. Inflammatory exudations — adenitis. — The 
continuous current is sometimes of great use for pro- 
moting the resolution of other chronic conditions due to 
inflammation. In enlarged lymphatic glands, Remak 
and many other writers have mentioned this effect, or 
reported cases. I have myself had under treatment a 


patient with numerous enlarged lymphatic glands of 
the neck which decreased very notably in size under 
electrical applications. In the Archiv. d' elect, medicale, 
vol. i., will be found an admirable paper on this subject 
with reports and summaries of twenty-three cases by 
Dr. Labat-Labourdette. He recommends the negative 
pole and considers the method of great value in cases of 
simple chronic adenitis or in tubercular adenitis in its 
early stages. 

Moritz Meyer* has seen deep cicatrices in muscle 
soften and disappear, and periostitis from gunshot 
injuries absorbed with remarkable rapidity. Both 
effects were procured by the use of the positive pole. 
Cheron again has seen stiffness of joints and plastic 
exudation from gunshot wounds removed chiefly by the 
application of the kathode. 

Keloid scars have also frequently been reported to 
have disappeared under electrical treatment, but it 
must be borne in mind that they may fade away 

231. Orchitis. — Scharff {Centralhl. f. Krankh. d. Ham 
mid Sex. Organe, i, 1894) claims to have employed 
electricity successfully in the treatment of cases of 
epididymitis. He does not wait until the affection has 
become chronic, but immediately and during the acute 
stage applies the anode to the lower part of the scrotum. 
The patient being in the dorsal position, a large elec- 
trode, with a maximum current of half a milliampere is 
employed, the duration of the application being three 
minutes on the first occasion ; this is afterwards 
increased to five and ten minutes, the increase beings 
very gradual. The weak constant current thus em- 
ployed should be carefully gauged with a sufficiently. 
* Quoted by Erb, •' Electrotherapeutics." 


sensitive galvanometer, and the current closed insensibly 
with the aid of a rheostat. No unpleasant sensation 
should be thus produced, but the patient will subse- 
quently on palpation be able to observe a considerable 
diminution or total disappearance of the tenderness 
which had previously existed. While in the same posi- 
tion a suitable suspender is applied, and the patient 
then allowed to walk about. Towards the seventh day 
the current can be increased to three milliamperes, the 
same electrode, however, being still used for a few 
days, when it can be somewhat reduced in size. The 
kathode is placed above the groin and on the abdominal 
wall. By this treatment, rest in bed can usually be 
dispensed with, the other advantages over the older 
methods being rapid and marked relief of the pain from 
the first, and greater rapidity in the disappearance of 
the swelling. Onimus also speaks very favourably of 
the good effect of electrical treatment in orchitis, and 
Dr. Picot, of Tours, has reported good results in forty 
cases ; they used currents of about five milliamperes. 

Dr. Duboc,t of Rouen, has reported two cases of 
chronic orchitis and epididymitis following gonorrhoea 
treated successfully by electricity, one had lasted for 
eighteen months in spite of much medication, the other 
for nine months. In both cases the swellings disap- 
peared rapidly and completely after about six applica- 
tions. Two pads were used, one in front of the testicle 
and one behind ; both were moistened with a tw^enty 
per cent, solution of iodide of potassium, a battery 
current of twenty milliamperes was used for ten 

232. In serous effusions. — Ascites and hydrocele 
have been treated by electricity and several writers have 

t Arch, d^elect. incdicale, 1894. 


reported favourably of the treatment. In ascites the 
induction coil current applied energetically for fifteen 
or twenty minutes so as to set up vigorous and repeated 
contractions of the muscular walls of the abdomen, has 
been followed by increased flow of urine and disappear- 
ance of the ascites. The prospects of permanent cure 
of course depend upon the cause of the ascites in each 
particular case. 

It is probable that battery currents might act even 
better than coil currents for the relief of this condition, 
by their greater action upon the vascular system of the 
abdominal organs. 

233. Corneal opacities. — Alleman"- in a valuable 
paper on applications of electricity to ophthalmology, 
gives an account of the treatment of corneal opacities 
by the continuous current. He says : " That from the 
observation of a number of cases, extending over a con- 
siderable time, he is convinced that the use of electricity 
promises the only treatment of avail in corneal opaci- 
ties of long standing." The kathode is applied to the 
cocainised cornea, and has the form of a silver rod, 
seven milliamperes in diameter, the flat end being used ; 
from one half to four milliamperes for one or two 
minutes are used. He has satisfied himself by strict 
tests that the results are really good. More care is 
needed with recent scars than with older ones. 

More recently several experimenters in this country 
have confirmed these observations and have reported 
their experiences in the British Medical Journal. Syne- 
chiae have also been frequently observed to fade and 
disappear under applications of the battery current 
through the closed eyelids. Those who are interested 

* Bigelow, " System of Electro-therapeutics," F. A. Davis & Co., 
Philadelphia and London. 


in the subject will find a useful paper by Dr. Pansier of 
Avignon in the Arch, d' electvicite medicale, 1894, with 
notes of twenty-four cases. 

234. Cutaneous affections. — Electrical applications 
to chronic ulcers of the skin will improve its condition 
and promote healthy cicatrisation, a layer of moist lint 
or absorbent wool should be laid over the ulcerated 
part and the electrode applied to this, or the current 
may be caused to reach the skin through a locally 
applied bath. I have seen prompt and permanent 
healing follow treatment by the interrupted current of 
an obstinate varicose ulcer of long standing. Patients 
who are taking a course of electric baths usually lose 
any acne of the skin of the back from which they may 
have been suffering at the commencement. 

Other observers have noted that obstinate pruritus 
can often be cured by the brush discharge ; and it can 
also be relieved by other electrical applications. 

These facts all show that the nutrition of the skin can 
be markedly influenced by electrical applications ; and 
the warmth and redness which is produced by electrical 
treatment of a part is another sign of this direct effect 
upon the cutaneous circulation. It has long been 
known that chilblains respond favourably to electrical 
treatment. Many things point to the probability that 
electricity, will some day occupy an important place in 
the treatment of skin diseases. The static breeze, the 
brush discharge from the Tesla coil, and the Rontgen 
rays all show marked effects upon the skin which can 
often be turned to good account in treatment. 

Dr. Marquant''' has reported a series of twenty-three 
cases of eczema and eczematous ulceration treated by 
the electrostatic brush discharge with very good results. 
* Arch, d'electricitc medicale, 1894, PP- S^Q, 385. 


His method had previously been tried by Prof. Doumer, 
who has also published a communication in the same 

The patients were placed on an insulating seat con- 
nected to the negative pole of the machine, and the 
positive pole was connected to a pointed electrode and 
held close to the affected part. In his concluding 
remarks, he says that the beneficial effect was superior 
to that obtained by any other kind of treatment. It 
was more quickly produced in those patients whose 
general health was good, than in those who were con- 
stitutionally unsound. The local pain, and the con- 
gestion and discolouration round the ulcers quickly 
disappeared, and healthy cicatrisation commenced 
rapidly. Oudin (§ no) has reported a number of cases 
treated successfully by high frequency discharges. 

235. Myalgia. — This is the name given to those 
pains which are felt in over-fatigued muscles ; when 
patients are in a condition of debility, the amount of 
muscular exertion which sets up these myalgic pains 
may be so small that the connection between them and 
their true cause may be entirely overlooked. Hence 
myalgia is constantly confounded wath hysteria, rheu- 
matic, spinal, and other diseases. f The symptoms are 
pain in the muscles, made W'Orse on movement, and 
tenderness. The skin over the muscles may also be 
very tender. The pains are often referred to one of the 
tendinous insertions of the affected muscle, and the 
trunk muscles are most commonly affected. Dr. Inman 
mentions as common seats of myalgic pains (i) the 
trapezius at its insertion into the occipital bone and 
into the spine of scapula ; (2) the spines of the dorsal 

* Idem., p. 141. 

f Inman on " Myalgia," Churchill, i860. 



and lumbar vertebrae (origins of spinal muscles) ; (3) the 
front of the chest (origin of pectoralis major and minor) 
producing infra-mammary pain ; (4) at the margins of 
the ribs, or at the pubes (insertions of recti abdominis). 

Myalgia may exist in persons who are apparently 
healthy, and it may be difficult to decide what is the 
particular cause of the muscular fatigue which they 
suffer from ; at the same time their pains may be very 
obstinate and very troublesome, and may resist all 
treatment until the diagnosis is clearly established, and 
rest for the affected muscles can be contrived. The 
movements which specially aggravate the pain must be 
carefully ascertained in order to decide upon the exact 
muscle which is at fault. General or local electrical 
applications may so improve the tone of the muscles as 
to enable them to perform without fatigue the work 
they are called upon to do. Local treatment acts use- 
fully too by improving the circulation in the muscles. 
The battery current up to 20 milliamperes may be used, 
the anode to the painful parts, the sitting may be ter- 
minated by a few reversals. This is the method 
advised by Erb. Induction coil applications to throw 
the muscles into contraction and exercise them are 
also useful. 

236. The urinary organs. — Incontinence of urine 
is a symptom for which much can be done by electrical 
treatment. The cases of this complaint which are met 
with fall under two distinct groups. In one, there is 
want of tone in the sphincter of the bladder, and urine is 
expelled involuntarily during any muscular effort which 
involves the action of the abdominal muscles ; and in 
the other the muscular apparatus is normal, but the 
patients suffer from incontinence when asleep. 

In women it is extremely common for there to be 


some inefficiency of the former kind, and in consequence 
a little urine is apt to be expelled from the bladder 
during muscular effort such as lifting a weight or during 
coughing or sneezing. If the weakness of the sphincter 
be rather more pronounced the incontinence becomes 
troublesome and annoying, and advice may be sought. 
The weakness of the sphincter may also be due to some 
dilatation or injury of the urethra, for example, during 
parturition or after a digital examination of the bladder. 
The tone and power of the female urethra can be 
strengthened by electrical applications, and the patient's 
comfort may in this way be greatly increased. I have 
notes of a patient who suffered from incontinence of this 
kind, for which she was obliged in the daytime to wear 
an urinal apparatus, and she was always wet and un- 
comfortable. A course of electrical treatment com- 
pletely cured her. In another case, equally successful, 
the incontinence was the result of an operation upon 
the urethra for the relief of some painful condition, 
possibly a caruncle. Since the operation the patient 
had been unable to hold her water, which escaped 
during any muscular exertion, so that her condition 
was most disagreeable to herself. After four or five 
weeks treatment she was quite well, and able to lift and 
carry her baby, a strong child a year and half old, 
without any leakage from the bladder. Other similar 
cases might be brought forward in which electrical 
applications have given great relief in this condition. 
Even when the incontinence is part of a paraplegic 
condition, treatment applied to the bladder may be of 
service. I have notes of two women who received 
injuries to the spine through jumping out of windows. 
They were referred to me for electrical treatment for 
their incontinence, and in both the power of the bladder 

EE 2 


seemed to be improved by treatment. At the same time 
they were and had been improving generally before 
coming under my care, and therefore the results of the 
electrical treatment they received are not so conclusive. 

Another patient who had incontinence as the result 
of a long railway journey without any opportunity of 
passing urine was quickly restored to health by 
electrical treatment. 

The treatment of incontinence due to weak sphincter 
is given in the next paragraph. 

237. Nocturnal incontinence. — This affection has 
a totally different pathology to that of the kind of 
incontinence already discussed. In nocturnal incon- 
tinence the patients are quite able to pass or to retain 
their urine so long as they are awake, but when asleep 
the bladder is apt to empty itself without awaking 
them. It is due to a persistence of the infantile condi- 
tion of micturition. The education of a child includes 
the education of inhibitory centres which bring the 
reflex mechanisms of micturition under the influence 
of the will, so that the action of the bladder is con- 
tinually controlled. If the control be imperfect the 
bladder may empty itself whenever the higher centres 
are in abeyance, as during sleep. A person suffering 
from nocturnal incontinence may pass water uncon- 
sciously in the daytime when asleep in a chair. As a 
rule sleep is very sound in patients who are the subjects 
of enuresis nocturna. 

Electricity is of use in enuresis nocturna because it is 
able to stimulate the centres, both cerebral and spinal, by 
producing painful local impressions which tend in time 
to bring the inhibitory cerebral mechanism into more 
close relation with the reflex centres in the lumbar cord. 
It is important to try to combat the tendency to very. 


deep sleep which exists in many of these patients. 
This may be attempted in various ways ; for example, 
the number of the bedclothes should be reduced, so that 
the patients lie a little chilly at night ; and a clock which 
strikes the hours is also a useful thing to have in the 
bed-room, especially if the patient can be taught to 
awake when the clock strikes twelve, or any other hour 
which may be specified. They must be taught to 
practise holding the water as long as possible by day, 
so as to accustom the bladder to become more tolerant 
of its contents and to train the influence of the inhibi- 
tory centres by their exercise. 

In children with enuresis nocturna it is important to 
search for any reflex irritation and to remove it when 
possible. Thus worms, oxaluria, a narrow meatus, or 
phimosis, if present, must be dealt with before resorting 
to electrical treatment. 

A very common type of incontinence in female 
patients is that of nocturnal incontinence complicated 
by a weak sphincter which causes them to wet them- 
selves by day as well. These cases are obstinate 
under treatment but perseverance will very generally 
cure them in the end. 

The best mode of application for cases of incontinence 
with weakness of the sphincter in women and girls is to 
introduce a bare metal sound into the urethra as one 
electrode, and to place the indifferent electrode upon 
the lower dorsal region of the back. The sound must 
not enter the bladder for more than a very short dis- 
tance, otherwise but little current will pass to the walls 
of the urethra. 

For purely nocturnal incontinence, applications to the 
perineum will usually answer quite as well as the pas- 
sage of a sound, and the latter may, therefore, be 


reserved for the more troublesome cases ; the use of 
a perineal electrode makes the operative procedure 
more simple and less formidable to the patient. Fig. 79 
shows an electrode of suitable shape. It consists of 
an acorn-shaped piece of metal fitted with a handle, 
and it is so contrived that its wash-leather cover can 
be changed in a moment after each application. A 
ring of vulcanite is pushed on over the piece of wash- 
leather to hold it in place. 

The electrode is to be placed upon the perineum in 
male children, and at the same place or between the 
labia in females. The currents used must be decidedly- 
painful in order to produce a suitable impression upon 

Fig. 79. — Electrode for enuresis. 

the nerve centres. It is useless to undertake the elec- 
trical treatment of incontinence without direct applica- 
tions to the perineal region. Where it is desired to 
avoid all manipulations of these parts the treatment 
must be done by a nurse, or it may be carried out by 
applications in an electric bath, using a pad pressed up 
between the thighs, outside the bathing dress, in place 
of the ordinary foot plate. The current then passes 
as desired into the perineal area. It is very important 
not to allow incontinence of urine in children to be left 
untreated in the hope that they may outgrow it, because 
in girls after puberty the local applications may be a 
source of great embarrassment. In the treatment of 


incontinence of either of the types described, the induc- 
tion coil current appHed strongly for eight minutes, and 
followed by a battery current of five to ten milliamperes 
with reversals every five seconds for three or four min- 
utes, seem to give the best results. The constant cur- 
rent without reversals should not be used for fear of 
injuring the skin and mucous membrane. Soreness or 
ulceration may be produced by the constant current 
unless it be carefully watched. 

In retention of urine occurring in hysterical subjects 
any painful local electrical treatment would probably 
prove effectual. 

258. Constipation. — Peristalsis can be set up by 
electrical currents applied through the abdominal walls, 
and chronic constipation can be permanently relieved 
by its use. The poles may be placed one on the lumbar 
spine and the other on the surface of the abdomen, they 
should be of large size ; the abdominal electrode should 
be moved over the whole surface of the belly for a 
period of five or ten minutes. After a few applications 
the bowels become more regular. Dr. Wahltuch''' has 
reported seven cases in which the continuous current 
produced good results. His method was to use a large 
sponge for the positive pole, and an ordinary medium- 
sized one for the negative. The former was applied to 
the epigastrium, while the latter was slowly moved 
over the whole abdominal surface, "in the direction of 
the intestinal canal from the duodenum to the sigmoid 
flexure," where it was finally fixed, and the current 
of from five to thirty Leclanche cells allowed to pass 
steadily without interruption for ten, twenty, or thirty 
minutes. The operation was repeated every other day 
for periods of from three to six weeks. The bowels 
* British Medical Journal, 1SS3. vol. ii., 623. 


gradually became regular in their action, although all 
aperients and enemata were stopped, and they remained 
so after the cessation of the treatment. 

Many other writers have reported similar results, and 
I have myself obtained notably good results in some 
cases, though not in all. 

Another plan, for obstinate cases, is to introduce a 
bougie electrode (fig. 80) into the rectum, the other 
pole being kept on the abdomen as before ; and to 
avoid risk of setting up ulceration and soreness of the 
rectal mucous membrane, a combined douche and elec- 
trode has been devised by Boudet de Paris, and in 
France a large number of cases have been treated for 

Fig. 80. — Rectal elertrode combined with douclie. 

obstinate constipation by means of it, and with great 
success. It has even been used for cases described as 
intestinal obstruction. It is obvious, however, that the 
nature of the intestinal obstruction should be fairly well 
made out before undertaking to treat it by electricity. 

An interesting article on this subject by Dr. Larat, 
of Paris, will be found in Bigelow's " International Sys- 
tem of Electro-Therapeutics.'"'' A similar electrode has 
been proposed for vaginal applications. The current is 
conveyed by the stream of water and electrolytic injury 
to the mucous membranes is avoided. 

When there is constipation from want of tone in the 
* F. A. Davis & Co., Philadelphia and London, 1894. 


muscular walls of the intestines, or of the abdominal 
muscles, with tendency to flatulent distension, a daily 
treatment by electricity does much good, and the dimi- 
nution in the size of the abdomen is easily perceptible 
after a time. 

239. Sexual disorders. — Various morbid sexual 
conditions have been treated by electricity. The 
nervous supply of these organs is almost identical m 
position with that of the bladder and rectum, and the 
seat of application is somewhat similar in both cases. 

Erb has advised that a small button-shaped electrode 
connected with the positive pole be held to the peri- 
neum, and another larger electrode (negative) be moved 
slowly up and down the lower dorsal and lumbar spine. 
The current may be from five to ten milliamperes, 
according to the tolerance of the patient, and the time 
occupied may be ten minutes. Applications daily 
for a week, then every other day. In this way the 
symptoms may be dispelled. Local treatment by 
means of the wire brush has also been proposed for 
sexual debility. Electricity is in no way a sovereign 
remedy for this class of patient, and the restoration 
of lost sexual powers is generally a vain hope, except 
where the troubles are mental rather than physical. 
Even then medical treatment cannot do very much. 

240. Diseases of women. — Electrical methods are 
largely made use of in gynaecological practice, not only 
for the sake of obtaining the direct effects (stimulating, 
sedative, or trophic) of electricity, but also for electro- 
lysis, and the galvano-cautery (see later chapters). 
Much attention has been directed to the subject of 
the electrical treatment of fibro-myoma, and an im- 
mense amount of literature has been produced since 
the introduction of Dr. Apostoli's method of treating 


that complaint by electrolysis of the uterine mucous 
membrane. His methods and results will be con- 
sidered in the next chapter. 

241. DysmenorrhoBa. — The effect on painful men- 
struation of the statical breeze has been referred to in 
§ 108. It is a mode of treatment which is easy and 
gives good results in many cases. The positive charge 
with the negative breeze to the loins and spine is not a 
disagreeable mode of treatment. It should be given 
daily for a week before the date of the appearance of 
the menstrual flow. 

242. The vomiting of pregnancy. — Drs. Gautier 
and Larat''' have described a series of cases, eleven in 
number, in which the battery current, stabile, arrested 
obstinate vomiting of this kind. The positive pole is 
applied above the clavicle between the attachments of 
the sterno-mastoid muscle, while the negative pole is at 
the epigastrium, the current should be of eight to ten 
milliamperes, turned on and off very gradually, and 
continued for fifteen minutes. It may be applied 
several times daily in severe cases. In from 24 to 48 
hours from the first application the vomiting ceases 
altogether, or is very greatly alleviated. 

243. Amenorrhcea. — Electricity has been employed 
in the treatment of this condition for a long time. 
Dr. Golding Birdf had a very high opinion of the 
value of shocks from the Leyden jar for curing this 
symptom, and writes at some length upon it in his little 
book. His method was to transmit through the pelvis 

* " Traitement par I'electricite des Vomissements Nerveux, et en 
particuliere des Vomissements incoercibles de la Grossesse," Paris, 

t Golding Bird, " Electricity and Magnetism," 1849, Lecture V., 
and Appendix B. 


twelve shocks in succession from a small Leyden jar, 
the discharge being directed from the sacrum to the 
pubes. The induction coil current applied to the uterus 
has also been found efficacious by Panecki and others 
in patients with amenorrhoea from sluggishness of the 
uterine functions apart from chlorosis. The electric 
bath, by its effect upon nutrition, acts as an indirect 
emmenagogue in chlorosis. When this condition is 
present general treatment is usually sufficient, and local 
applications are not called for, and indeed are unde- 
sirable. In healthy women in whom menstruation is 
regularly performed, electricity may certainly hasten 
the appearance of the flow, especially when it is applied 
to the abdomen or pelvic region. The electric bath 
may have the same effect. 

It is best to suspend general electrical treatment in 
women for a few days before the menstrual periods, 
otherwise the flow may be rendered excessive, and in 
pregnancy it is better not to employ electricity at all for 
abdominal or bladder troubles. 

244. In parturition. — In a paper read by Dr. Kilner 
before the Obstetrical Society,* the use of the induc- 
tion coil current is advocated during parturition. He 
found that uterine contractions could be excited or 
strengthened by its aid, though not in all cases. Some- 
times the resulting contractions were very severe and 
prolonged, indicating possible risk to the child. The 
applications seemed to diminish the pains felt during 
the labour, and after the birth of the child ensured a 
firm uterine contraction, and much diminished the risk 
of post-partum haemorrhage. Some medical men speak 
very highly of its value in childbirth, and make a prac- 
tice of carrying a small induction coil in their obstetric 
* British Medical jfonrnal, April, 1884. 


bag. It has also been of service in flooding after mis- 

It follows that caution is necessary before applying 
electrical treatment to the abdomen or pelvic organs of 
a pregnant woman. Dr. Golding Bird speaks of having 
produced a miscarriage as the result of the Leyden jar 
shocks used by him. 

245. The mammary glands. — Electrical stimula- 
tion applied to the mammary glands has been found 
useful for promoting the secretion of milk in nursing 

Two patients who were suckling their infants were 
treated in this way in the Electrical Department at 
St. Bartholomew's Hospital, for failure in their milk 
producing powers. In one case a decided improvement 
followed. In the other the results were doubtful. It is 
not often that the advice of medical men is sought for 
producing an increase of the mammary secretion. 

Cases are quoted by Drs. Beard and Rockwell. 

Electricity has also been recommended as a means 
of increasing the size of the breasts in cases where their 
development is defective. 

246. Guinea worm. — In the British Medical Jotmial, 
vol. ii., 1883, p. 1280, an account of the removal of a 
guinea worm with the aid of a battery w^as published by 
Mr. Alexander Faulkner. 

One pole was held in the patient's hand, and the other 
was applied to the protruding extremity of the worm, 
the application was continued for an hour wath gentle 
traction, and at the end of that time the whole had been 
extracted ; the usual process of withdrawing the guinea 
worm httle by Httle by traction for a few minutes daily 
is a very tedious affair, and may take weeks to complete 
it, even if the worm is not broken in the process. Mr 


Faulkner's explanation of the action of the current is 
that the worm is benumbed and rendered incapable of 

247. Suspended animation. — The aid of electricity 
is often invoked for the purpose of resuscitation when 
death appears to be imminent. It may be apphed 
either in the form of brisk general cutaneous stimula- 
tion, in cases of narcotic poisoning, or with the special 
objects of stimulating respiratory movements, or of 
acting upon the beat of the heart. 

In the first case the use of the induction coil, prefer- 
ably with a long secondary wire and the metallic brush 
electrode, is advised. The region of the body which is 
stimulated is not of special importance, the applications 
may be made to any part which is exposed, and con- 
venient of access. 

A considerable reflex effect is produced by this 
cutaneous stimulation, and if the dry brush and the 
long wire coil are used there is much less risk of pro- 
ducing fatigue or exhaustion of the patient, than if 
a short wire coil be used with moistened electrodes 
(§§ 72, 73). Stimulation of the face, especially of the 
nose and upper Hp, tend to act favourably upon respira- 
tion. Duchenne has shown that stimulation of this kind 
applied to the precordia or to the skin of the back in 
the lower dorsal region, also influences the respirations. 
At the former situation inspiration is chiefly promoted, 
and in the latter expiration. 

The phrenic nerves in the neck can be directly stimu- 
lated by the induction coil without difficulty, and con-, 
traction of the diaphragm will follow. No inconvenience 
seems to be produced by the proximity of the vagi. 
The method is as follows : — Two moistened electrodes 
of small size, about one inch in diameter, must be con- 


nected to the coil, one should have a key for making 
and breaking the circuit. These are to be applied 
under the posterior border of the sterno-mastoid mus- 
cles, which should be pushed forward, the key must 
then be closed and opened rhythmically about every 
two seconds, each closure causes an inspiration, ex- 
piration being allowed to take place during the inter- 
vals. This use of the induction coil to set up respiratory 
movements may be advantageously combined with 
mechanical artificial respiration by Silvester's method. 
Electrical stimulation of the phrenics in asphyxia, and 
in chloroform poisoning, has been successfully carried 
out. For further details Dr. F. W. Hewitt's book'"--' 
may be referred to. Stimulation of the epigastric region 
may cause expiratory movements by acting upon the 
abdominal muscles. 

Direct applications to the heart region do not readily 
affect the movements of that organ. If they do, the 
result is quite as likely to be harmful as useful. It is 
better therefore not to attempt it. 

248. Electricity as a test of death. — The elec- 
trical reactions of muscle have been proposed as a test 
of death. The contractility of living muscles persists 
for a few hours after death, and then disappears. 

If the muscles of a person supposed to be dead cannot 
be caused to contract by a strong induction coil current, 
life may be considered extinct, if they do contract it is 
possible that he may be alive. Certainly no person 
should be buried if his muscles are still normally con- 

Onimus and Legrosf have shown that there is a stage 
in the death of a muscle at which it gives the reaction 

* "Anaesthetics and their Administration," London, 1893. 
t " Traite d'electricite medicale," Paris, 1S88. 


of degeneration (§ 136), that is to say, the irritability to 
the induction coil disappears first, while the response to 
direct battery current stimulation continues, giving rise 
to a sluggish contraction. This change sets in about 
four hours after death, and they relate a case in which 
the reaction enable them to specify correctly the time at 
which death had occurred. 




The laws of electrolysis. Actions in living tissues. Uses in surgery. 
Removal of hairs. Moles and Warts. Nasvus. Port wine 
mark. Aneurysm. Stricture of the urethra, of the oesophagus, 
of the rectum, of the Eustachian tube. Electrolysis in fibro- 
myoma. Dr. Apostoli's methods. Extra-uterine foetaiion. 

249. Electrolysis. — The laws according to which 
substances are broken up by the passage of the electric 
current, and the terms used in considering the portion 
of a circuit in which electrolysis is occurring, were 
shortly given in §§ 36, 37. According to the hypothesis 
of Grotthus the molecules are arranged under the di- 
rective action of a current in lines between the anode 
and kathode, and all along this line a continual decom- 
position and recombination takes place, which, how- 
ever, is only manifested at the poles under ordinary 
circumstances. It is perhaps better to look on an 
electrolyte with Clausius, as a body whose molecules 
are continually undergoing dissociation and recombina- 
tion, even when no current is passing. When, how- 
ever, an electric stress is set up, there is a directive 
force brought to bear upon the molecules that are in a 
free state, and a migration is set up, the electro-negative 
ions passing towards the anode, the electro-positive 
ones towards the kathode ; if the electric stress is suf- 
ficient to overcome the tendency of the dissociated 
molecules to recombine, decomposition takes place. 


Secondary reactions. — The view usually taken is that 
the actual products of electrolysis are not given off at 
the electrodes ; in general they react with a further 
portion of the electrolyte or of the solvent, or with the 
substance of the electrodes, and the products of this 
secondary reaction appear. Thus, for example, if a 
solution of sodium sulphate be submitted to electrolysis 
between platinum electrodes, the ions are sodium and 
the radical SO^^, but the former instantly decomposes 
the water present, and forms sodium hydroxide and an 
equivalent quantity of hydrogen, while the latter breaks 
up into SO 3, sulphur trioxide, which combines with 
water to form sulphuric acid, and oxygen, which is 
given off. The result is that the liquid about the anode 
becomes acid, while that at the kathode is alkaline. Of 
course, if the whole is allowed to mix, the two neutra- 
lise each other, and the only effect of the electrolysis is 
that some water has been decomposed. 

If the electrodes consist of metals that are capable of 
being acted on by the ions action will take place and 
thus the anode will be dissolved if the anion is capable 
of forming a salt with them, thus a copper anode is 
rapidly dissolved if used to electrolyse the salts of the 
mineral acids. 

When mixed electrolytes are submitted to electrolysis 
the most electro-negative ion of the mixture generally 
makes its appearance first, but it has been shown 
experimentally by Hittorf that all electrolytes present 
are concerned. 

250. Electrolysis of living tissues. — The electro- 
lytic effects produced by a current in passing through 
the body appear chiefly at the surfaces of the electrodes. 
These are local effects due to the chemical action of the 
substances set free by primary or secondary reactions 



in the electrolyte. They may be complicated by solu- 
tion of the anode if it is made of a metal that forms a 
soluble chloride. Smaller effects may be looked for 
throughout the body, due to the chemical action be- 
tween different electrolytes separated by cell walls or 
other semi-permeable septa, migration of the ions, or 
transference of the electrolytes due to electrical osmosis. 
These effects will be seldom perceptible with such 
currents as are used in treatment. 

In a study of the electrolysis of animal tissues, 
Dr. G. N. Stewart''' found that practically the whole 
of the conduction through animal tissue is electrolytic, 
and the electrolytes are the saline constituents ; the 
changes produced in the proteids (coagulation, forma- 
tion of acid and alkali albumen) are brought about by 
secondary chemical actions. Striking changes in the 
distribution of the salts can be produced which might 
be sufficient to modify nutrition profoundly. 

In the electrolysis of animal tissues there is a double 
decomposition. The salts contained in the tissues split 
up, the alkalies are liberated at the kathode, and the 
acids at the anode. The alkali metals decompose the 
water in the neighbourhood of the kathode, liberating 
the hydrogen, which appears as bubbles of gas. The 
caustic potash or soda thus produced saponifies the 
animal tissues and produces a soft deliquescent eschar, 
which is said to heal with less contraction than an 
eschar produced by either a wound, a burn, or an acid, 
and, therefore, is the most suitable to obtain when it is 
particularly necessary that the least possible contraction 
shall subsequently take place. The acids from the salts 
contained in the animal tissues are liberated at the 
anode ; generally oxygen is liberated, but the reaction 
* Lancet, Dec, 1890. 


which takes place at the anode depends very much 
on its composition. If the electrode is made of zinc, 
chloride of zinc is formed, which exerts its own specific 
action on the tissues. By using anodes of iron or 
copper the local effects of salts of these metal can be 

The caustic effect of an electrode connected with the 
negative pole of a battery has advantages over the use 
of the ordinary caustic soda or potash. As pointed out 
by Dr. Poore, it can be applied to parts difficult of 
access, as the male urethra, or uterine cervical canal. 
It can be applied to these regions and others, such as 
the larynx, pharynx, or nasal duct, where the appli- 
cation of other caustics is attended with danger or 
difficulty. Its effects are limited to the points touched 
by the electrode. The duration and extent of the 
caustic action is entirely under the control of the 

251. Uses in surgery. — Electrolysis is used in sur- 
gery as a means for producing destruction of tissue in a 
simple and minute localised manner. This is effected 
indirectly by the action of the chemical bodies liberated 
at the poles during the passage of the current. As these 
bodies are different at the two poles, so the actions 
which take place at the poles differ from one another 
to a certain extent. The advantages of being able 
to localise the effects so precisely is well seen in the 
operation for the removal of hairs, for here the destruc- 
tive effects are confined to such a minute area in the 
immediate neighbourhood of the hair follicle that no 
perceptible scar is produced although the hair follicle 
is eradicated. Electrolysis has been used for the 
following purposes: — (i). The removal of superfluous 
hair, of moles, and of warts. (2). Destruction ■ of 

FF 2 


naevi. (3). Coagulation of blood in aneurysms. (4). 
Destruction of strictures in the urethra, lachrymal 
canals, oesophagus, rectum, and Eustachian tube. (5). 
Destruction of cancerous growths, and (6) for the relief 
of symptoms in fibro-myoma of the uterus. This last is 
brought about as a secondary process which has been 
found to follow electrolytic destruction of the uterine 
mucous membrane. 

252. The removal of hairs. — If a fine needle con- 
nected to the negative pole of a battery of four or five 
cells be introduced into a hair follicle, electrolysis takes 
place round the needle when the circuit is closed, and 
the hair follicle is destroyed by the alkali produced ; 
the hair can then be removed easily and does not grow 

The method of operating is as follows : — The patient 
should recline in a good light. Having placed the 
indifferent electrode (anode) in contact with a conveni- 
ent part of the patient's body, the kathode is attached 
to a fine platinum wire set in a handle, the current 
collector is turned on to take up four cells into circuit, 
the operator then introduces the needle as closely as 
possible to the root of the hair, holding it in the proper 
direction for it to enter the follicle ; the needle passes 
down readily to the required distance, one-eighth or 
one-tenth of an inch, a current of about three milli- 
amperes passes, slight effervescence is seen at the 
orifice of the follicle, and at the end of five seconds or 
so the needle is withdrawn. As a rule the hair can 
then easily be lifted out by a forceps ; if it still remains 
firm, the needle may be introduced a second time until 
it is loosened, though this is not a very good thing to 
do ; it is rather better to leave the hair until another 
day ; the current should be just strong enough to pro- 



duce slight frothing. The best way to learn how to 
perform the manoeuvre is by a few preliminary experi- 
ments on oneself. There is a certain 
amount of pain, but it is within the limit 
that can be borne without flinching, and 
an anaesthetic is not necessary. Cocaine 
need not be applied. 

It is best to use for the needle a very 
fine platinum wire, blunt pointed, because 
such a needle is less likely to penetrate too 
easily and so pass away from the hair fol- 
licle. It can be sterilised before use by 
heating to redness, and is better than a 
steel needle. The current must be closed 
before the needle has been placed in posi- 
tion. A key in the handle is therefore 
unnecessary and troublesome. 

A good deal of practice is required to 
perform this little operation skilfully, no 
force must be used in removing a hair, if 
force is used the hair will come out before 
the follicle is destroyed, leaving its root 
behind, and a new hair will grow up from 
it. When many hairs are to be removed 
they should be done at successive sittings. 
Patients as a rule become restless from the 
pain of the operation after a time, and as 
soon as signs of this begin to appear, it is best 
to suspend the operation. It is possible, 
however, with a good patient, to remove 
thirty or forty hairs at a sitting. A tiny 
eschar with a small zone of redness is left round the 
follicle. Several hairs in close proximity should not 
be attacked at one time, for fear less the nutrition of 

Fig. Si.— Needle 
electrode for epi- 


the skin should be so much interfered with as to lead 
to a small ulcer and consequent scar, but the hairs 
should be removed sporadically, until at the last few 
sittings the few remaining ones can be gleaned off and 
the place left smooth and bare. If the patch of hairs is 
small the sittings must be less frequent, once a week 
being quite often enough. When there is plenty of 
room to attack a fresh part each time the sittings may 
be repeated more often, care being always taken not to 
injure the skin at any one point too much. 

It is as well to caution patients that there will be a 
certain percentage of returning hairs, but that these 
can be dealt with a second time if any should so return. 

It is very easy to overdo the treatment and leave 
scars. It is not wise to attempt the removal of a fine 
downy growth on the upper lip of young women. 

253. Trichiasis. — The removal of eyelashes for 
trichiasis is satisfactorily accomplished by electrolysis, 
but it is difficult to carry out owing to the sensitiveness 
of the part, and the fineness of many of the most 
troublesome hairs. I have had under treatment 
several cases suffering from this complaint. In one, 
at the commencement of the treatment both corneae 
were hazy, the result of the continued irritation by the 
turned in eyelashes ; the removal of the eyelashes was 
persevered with until every one had been removed ; 
by that time the corneae had recovered perfect trans- 
parency. The patient has continued free from trouble 
from his eyelashes since. 

254. Moles. — The best treatment for smaU hairy 
moles is epilation ; when the hairs have been removed 
very little will be seen of the mole, for a good deal of 
the pigmentation of the skin between the hairs will 
disappear when they have been taken out, and the 


prominence on which they often grow will also dis- 
appear ; but if there be much pigmentation the best 
treatment is by puncturing the mole vertically all over 
its surface, using a negative needle and seven or eight 
cells. The cocaine guaiacol mixture (§ 125) can be 
very well used to render the part insensitive. If the 
moles are small and pedunculated it is best to electro- 
lyse after transfixing them with the needle. 

255. NsBVUS. — Electrolysis is a very convenient way 
of destroying naevi, and in special cases it is superior 
to all the other methods, but, to secure first rate results, 
a certain amount of practice is necessary, and several 
sittings are required except for the very small ones. 
The chief art in treating a naevus lies in the careful 
regulation of the current used and in knowing when to 
stop. It is easy to electrolyse a naevus in such a way 
as to destroy it and cause it to slough away completely, 
but this leaves a large scar and is not the best way of 
attaining one's object. The object to be aimed at in 
the electrolysis of nsevi is to carry the destructive 
action just so far as to coagulate the blood and break 
up the blood-vessels without producing a general necro- 
sis and sloughing of the whole. When the naevus is 
entirely subcutaneous, it is most important to save the 
skin, for then the naevus is destroyed without any scar 
except at the minute points where the needles were 
introduced. When the naevoid tissue is quite super- 
ficial, and very florid, and involves the actual thickness 
of the skin, it is difficult or impossible to destroy it 
without some sloughing. 

The usual plan of treatment is as follows : — Needles 
attached to one or both poles of a battery are introduced 
into the naevus, a galvanometer being included in the 
circuit ; the current is then very gradually raised from 


zero up to 20, 30 or 40 milliamperes. If both poles are 
used care must be taken that needles of opposite poles 
do not touch one another, for if they remain in contact 
the current simply runs to waste through the metallic 
circuit so produced, and the nsevus tissue is unaffected ; 
if they come into momentary contacts, the patient 
receives a shock each time they touch and separate. 
Soon after the commencement of the operation the 
tissues round the needles begin to change colour ; 
round the positive needles there is hardening and 
pallor, and round the negative needles frothing is 
produced with the evolution of hydrogen gas. The 
positive needles become firmly adherent to the tissues in 
which they are imbedded, and force is required to with- 
draw them, on this account bleeding is more likely to 
occur with the positive than with the negative needles. 
The negative needles become very loose and are apt to 
slip out, but they must not be allowed to do so, for the 
current must not be suddenly interrupted for reasons 
already mentioned. If the tissues round the needles 
become livid or blackened sloughing of the part will 
follow. This change shows itself first at the negative 
pole. The position of the needles must be changed 
before this, by taking them out and re-inserting them 
one at a time in other parts of the naevus, until the 
whole of it has been treated. 

The naevus becomes swollen and harder during the 
process of electrolysis, and the skin round it becomes 
reddened. About five minutes is a suitable length of 
time to continue the electrolysis, but this should be 
varied with the size of the naevus. If the naevus is 
very extensive it must be dealt with in detail, part 
being attacked at each sitting until the whole has been 


The needles are to be withdrawn after the current 
has been lowered and must not be plucked out while 
the current is still running strongly. The negative 
needles are easily withdrawn, but the positive may be 
adherent and should be twisted out gently. A little 
bleeding may follow from one or two of the punctures, 
but it is rarely of any importance. The after-treatment 
is simple. Collodion containing iodoform, one drachm to 
the ounce, is to be painted over the naevus ; this can be 
left for four or five days, it should then be removed, 
and the place treated with boracic ointment. If any 
suppuration or local sloughing should develop, a poul- 
tice at night, with some zinc lotion by day, will be a 
suitable treatment. Many of the smaller nsevi dry up 
and need no second application. It is impossible to 
avoid some destruction of the skin and scarring when 
the ngevus is cutaneous, but the scars produced are 
much smaller than might be expected, and when seen a 
year or two afterwards they show remarkably little. 
Sometimes only one set of needles, usually the negative, 
is introduced into the naevus, the circuit being com- 
pleted through the patient's body by using a large pad 
for an indifferent electrode. In this case the resistance 
is higher, so a larger number of cells is required. There 
is a greater risk of shock or faintness, especially with 
naevi of the head and face, but with care the operation 
can be carried out successfully. This unipolar method 
is most suitable in cases where great nicety is needed, 
as, for example, in small nsevi about the eyelids or nose. 

Care must be taken that the pad electrode and its 
conducting wire are well covered and that no bare 
metal touches the skin anywhere, any oversight in this 
matter may lead to electrolysis where it is not wanted, 
namely, at the seat of the indifferent electrode. 



The rate of destruction depends upon the density 
(§ 112) of current in the part; if needles of both poles 
are introduced irregularly, it is very likely that the 
current may be concentrated round the points where 
they are [nearest together, and be very feeble in the 
more remote parts. The diagrams (fig. 82 and 83) 

Fig. £2.— Electrolysis of nasvus. Proper position of needles. 

Fig. 83.— Electrolysis of njEvus. Improper position of needles. 

represent the conditions under two different arrange- 
ments of needles, in the first the needles are placed in 
such a way as to be equidistant, and the density of 
current is therefore uniformly diffused. In the second, 
they are all very near together at the points and there 
the current is of far greater density than at the peri- 
phery of the naevus, the effect of such an arrangement 



would be to produce a slough at the centre, while the 
periphery would not be destroyed at all. In order to 
simplify the introduction of the needles in a proper 
manner, the writer* has devised an instrument (fig. 84) 
consisting of a handle to carry the needles ; two, three, 
four or five can be screwed into it, and they are so 
arranged as to be alternately positive and negative 
(see the smaller of the two figures). By this means 
the needles are kept at equal distances from one 
another throughout the operation, and they cannot 
touch accidentally, and they can be moved about 

Fig. 84. — Bipolar fork electrode. 

simultaneously inside the naevus so as to bring the 
whole of it under the action of the current. 

It is difficult to formulate a rule for the current to 
be used, but it is the density of current which is the 
important point, more so than the actual number of 
milliamperes employed. The current density should 
not exceed twenty milliamperes per inch of positive 
needle if it is desired to avoid sloughing in a naevus. 
Thus, with four needles introduced for a distance of 
one inch, two being positive, a current of forty milli- 
amperes would be amply sufficient, and with twice the 

* Dr. Lewis Jones, Brit. Med. jfouvnal, Feb. 20, 1892. " An 
mproved instrument for the electrolysis of n^vi." 


number introduced for half that distance the same 
current would yield the same effects. 

The cells of an ordinary portable battery will do very 
well for the occasional electrolysis of neevi, but as the 
current required tends to exhaust small cells rather 
fast, it is better to use larger ones when portability is 
not essential. The galvanometer must read up to fifty 
milliamperes. From twelve to twenty cells are suffi- 

The usual arrangement of wires for the attachment of 
the needles is shown in fig. 85. It consists of two 
parts, (i) a main lead from the pole of the battery, 
terminating in a binding screw, and (2) several secon- 
dary leads or branches, each carrying a needle, and 
attached to the binding screw of the main lead. The 
needles should be of platinum. Insulation of the 
needles is not important, and it is difficult to obtain an 
insulating coat which does not greatly increase the 
thickness of the needles and act as an obstacle to its 
introduction. Hard varnish, applied each time, is the 
best. The intention is that the whole of the bare part 
of the needle must be buried in the naevus, in order 
that an insulated part may be in contact with the skin, 
which is then attacked but little, and this diminishes 
the size of the marks w^hich will be left at the points of 
entry, and for this reason needles are required whose 
bare points are of varying length. When needles of 
one pole only are used, the other (indifferent) electrode 
must be a pad of good size, to diminish as much as 
possible the density of current at its surface of contact, 
and also to diminish the resistance. 

Care must be taken to prevent any spare needles from 
touching the patient's skin by accident, or they will 
corrode it at the point of contact. 



The needles are attached to the ends of the wires in 
various ways. Soldering is much the best. Unions 

Fig. 85.— Attachment of needles for electrolysis of nsvus. 

effected by twisting the wire round the needle are bad, 
for-they are apt to break adrift at a critical moment 


and give rise to shock. With large currents such 
shocks are undesirable in the case of infants under 

An anaesthetic should be given as the pain is severe 
during the passage of the current, though it does not 
persist after the operation is over. 

The needles may be introduced either in a direction 
parallel to the surface or vertically ; the former is the 
best when the naevus has any appreciable thickness. 

In some superficial naevi a multiple puncturing with 
a vertical needle gives the best results, sufficient skin 
survives between the punctures to preserve the mark 
from being truly cicatricial. 

The electrolytic treatment of nsevus is not so simple 
a matter as it may appear to be at first sight. Those 
naevi w^hich can be easily excised should not be at- 
tempted by electrolysis, which should be reserved for 
those w^hich are difficult to do by other methods. If 
the naevus is very small, that is to say, under a fifth 
of an inch in diameter, it may be completely destroyed 
in one sitting, and the resulting scar will not be of any 
great moment ; and here I would urge very seriously 
the importance of dealing with nsevus at the first pos- 
sible opportunity after birth. Naevi which are quite 
small at birth are often allowed to grow large before 
any interference is thought necessary, with the result of 
disfigurement, which might have been prevented by 
timely treatment. They should always be attacked at 
once. Unless naevi are large, the first apphcation 
should aim at complete destruction, or at least the 
major part of the naevus should be got rid of at the first 

Naevi may spontaneously disappear, but this is a rare 
occurrence, and the usual tendency of a naevus in the 


young baby is to grow rapidly. Indeed, after electro- 
lysis, a nasvus will often commence to grow afresh, 
although at the time of operating it seemed to have 
been completely destroyed. Such re-appearance may 
take place after a naevus had been perfectly healed for 
over two months. The margin of a nasvus is especially 
prone to start fresh growth, and must be treated as 
thoroughly as possible. 

Naevus is commoner in females than in males, and it 
is found on the head and neck more often than upon 
the trunk or limbs. Out of 173 consecutive cases in 
the Electrical Department of St. Bartholomew's, 121 
were in female, and 52 in male children ; in about three- 
fifths of these the naevus was situated on some part of 
the head or neck. I have once seen a naevus of the 
ocular conjunctiva. At the anterior fontanelle it is not 
uncommonly met with, and can safely be treated by 
electrolysis ; the needles of course must not be pushed 
into the brain. 

256. Metallic, electrolysis. — The use of copper 
needles for electrolysis has been advocated under this 
name, the intention being to deposit a salt of copper 
in the naevus or other tissue under treatment. More 
marked effects can be produced by copper than by 
platinum needles, and the metal does not appear to 
leave any permanent stain. The positive pole must be 
used. Instead of copper needles the ordinary platinum 
needles can be coated with copper electrolytically in a 
bath of sulphate of copper, using a piece of copper sheet 
for the anode and making the needles to be coated the 
kathode of a battery of one or two Leclanche or other 
cells ; the process only takes a few minutes, and the 
needles can then be taken out, washed and used for 
electrolysing a naevus. With copper needles the visible 


effect is rather different to that of electrolysis with the 
negative pole and platinum needles, and therefore a cer- 
tain amount of practice is required before one becomes 
an adept with the coppered needles ; but good results 
can be had, and especially when a more thorough de- 
struction of a part is desired. The tissues round the 
needle turn of a dull greenish colour. The negative 
pole must be used in the form of a pad electrode, as the 
deposition of copper from the needles takes place only 
at the positive pole. 

257. Port wine mark. — This form of naevus can be 
attacked by a tattooing process, using a fine needle, 
and inserting it vertically into the skin, the current 
used must be under five milliamperes, and the appli- 
cation at each point quite brief. There is no need to 
use several needles at once. The operation should pro- 
duce minute points of destruction without confluence of 
the resulting minute scars. The negative pole is best. 
If a port wine mark be closely scrutinised, the position 
of many of the capillaries can be seen, and these are the 
points into which the needle must be especially directed. 
The area affected must be treated in a sporadic manner 
at successive sittings as advised for the removal of 
superfluous hair. The result is a distinct improvement 
in the aspect of the surface ; the treatment must be 
carried out slowly. It is so slow a process that it is not 
often undertaken. 

258. Aneurysms. — Electrolysis has been tried for 
the cure of aneurysms, particularly for those which are 
not suitable for treatment by ligature or compression. 
In many of the cases recorded, some temporary increase 
of hardness has followed the operation, but the cures 
are but few, and the punctures made in the sac walls 
have sometimes led to haemorrhage. The piercing of 


the wall of the aneurysm by the needles, with the con- 
sequent risk of bleeding is the chief defect of the opera- 
tion ; it may be lessened by the use of needles insulated 
except near their point, so as to limit the electrolytic 
process to the interior of the aneurysm, and to prevent 
any action upon its wall. 

The method which is generally preferred is to intro- 
duce both positive and negative needles into the tu- 
mour ; the needles attached to the positive pole become 
corroded if they are made of steel, but this is not an 
objection, for coagulation is promoted by the salts of 
iron so produced. Ciniselli'-''' has collected twenty-three 
cases, of these six recovered, sixteen died, and one case 
disappeared from observation. Some of those reported 
as cured had relapses a few months later. See also 
Brit. Med. Joimial, 1890, vol. i., p. 1276, for a report 
of successful results after thirteen sittings in a case of 
aortic aneurysm. 

As far as can be made out from the details furnished, 
the electrolysis of aneurysm requires large currents and 
long sittings. Twenty, thirty, or forty cells have been 
used, and the application continued for half an hour or 
more. Assuming the internal resistance to have been 
100 ohms (it may have been much lower), and putting 
the electromotive force of the cells used at one volt 
a piece, then twenty cells would give a current of about 
200 milliamperes, and forty would give twice as much. 
This current if continued for half an hour, would be 
sufficient to set free a considerable amount of electro- 
lytic gases, and in some of the cases we read that the 
tumours became resonant to percussion after the opera- 
tion. The free acids and alkalies produced by the 

* " Treatment of Thoracic Aneurysms by Electro-puncture," 
Milan, 1870. 



electrolytic separation of the neutral salts of the blood 
would probably soon recombine in their passage along 
the blood stream. The clotting set up in the aneurysm 
is soft and diffluent. 

259. Stricture of the urethra. — Modern writers 
on this subject refer to Crussel, 1839, as the first to use 
electrolysis for the cure of this condition, and to Mallez 
and Tripier''' as the first to practice it systematically. 
A good deal has been made of the difference between 
electrolysis of a stricture, and destruction of it by the 
caustic alkali set free electrolytically at its surface, as 
though the former process were something essentially 
different and less injurious than the latter. It has also 
been claimed that the stricture can be cured without 
any destructive action upon the mucous membrane 
which covers it. It is probable that the yielding of a 
stricture during electrolysis is mainly due to its actual 
corrosion by the alkali liberated at the negative pole, 
and that the mucous membrane, because it is nearest 
to the electrode, must be the first part to perish, but it 
is possible that the current produces some interstitial 
absorption of the tissues of the stricture, in the way 
referred to in § 230. 

Mr. Bruce Clark in a paper on the subjectf says : — 
" Where I have had an opportunity of treating an 
orifice stricture it is clearly demonstrated that with 
such currents as one usually employs, no solution of 
epithelial continuity takes place," and again: — "That 
absorption does take place can be witnessed when a 
stricture at or within half an inch of the urethral 

* " De la guerison durable des retrecissements de I'urethre par la 
galvano-caustique chimique," Paris, 1867. 

t " The Treatment of Stricture of the Urethra by Electrolysis," 
The Practitioner. 1886. 


orifice is submitted to treatment. In these cases the 
surface of the epithehum is seen to be gradually con- 
verted into a glutinous saponaceous-looking material. 
If this be wiped carefully away, the surface is seen to 
he red and somewhat congested in appearance, but it 
is perfectly evident that the epithelium is not entirely 
removed with such currents as I am in the habit of 

In a paper read at the Annual Meeting of the British 
Medical Association, in 1886, by Dr. W. E. Steavenson, 
the following account of electrolysis of stricture 
occurs : — " No doubt this procedure will become one 
of the recognised modes of treatment of stricture. It 
may not be destined to become the most usual mode 
of treatment, because of the apparatus required, the 
numerous details connected with its application, and 
the great care and patience required for its successful 

" For the treatment of stricture of the urethra, the 
electrodes we have used are catheter-shaped gum-elastic 
bougies, ending in a metal nickel-plated piece connected 
to a binding screw on the handle. The indifferent 
electrode is placed upon the patient's back if he is in 
the recumbent position, or it may be placed on any 
other convenient part of the body. The metal plate is 
made positive. 

" An ordinary bougie is first passed down to the 
stricture, and by its means the distance of the stricture 
from the meatus is ascertained, and a mark made on 
the bougie. It is then found out what sized bougie 
w^ill pass the stricture. Say, for instance, it is ascer- 
tained that a No. 3 bougie (English) will pass ; a No. 5 
electrode is then taken and passed down to the stric- 
ture, where it is arrested. It can be made certain that 

GG 2 


the electrode is arrested at the stricture by previously 
marking it, after measurement and comparison with the 
bougie first passed. When the electrode is in position 
against the stricture, it is connected with the negative 
pole of the battery, the circuit is closed and the current 
gradually increased without breaks until the maximum 
strength is reached that it is intended to employ^ 
namely, about five or six milliamperes. The electrode 
is kept gently pressed against the stricture in the direc- 
tion of the ordinary course of the urethra. No force is 
used, but the current is allowed to do the work. The 
surgeon has to keep his attention continually applied 
to the electrode, so as to guide it in the right direction, 
otherwise a false passage may be dissolved into the 
side of the urethra. Therefore skill in passing a 
catheter is a requisition. In the hands of a surgeon 
who knows his way into the bladder, a false passage is 
not more likely to be produced than is the case in pass- 
ing an ordinary catheter. The electrode is to be kept 
gently pressed against the stricture in the normal direc- 
tion of the urethra until, from the dissolution of the 
obstacle in front of it, it passes into the bladder. The 
current then should immediately be cut off, and the 
bougie withdrawn. The duration of the operation 
depends upon the density of the stricture and the 
strength of the current used. 

" Although as a guide I have mentioned that the 
current should be about six milliamperes, the strength 
really used is regulated by the patient himself. One 
great object is to avoid giving pain, and by this means 
a too great destruction of tissue is prevented. We 
require our patient to be conscious ; therefore no anses- 
thetic is used, or indeed necessary, for the only sensa- 
tion produced is a slight pricking at the seat of the 


stricture. If anything amounting to pain should be 
complained of, the strength of the current has to be 
diminished. On removing the electrode, there is some 
times found on it some slimy matter like disintegrated 
tissue ; and the patient is often immediately after its 
withdrawal enabled to pass urine with increased facility 
and with very little discomfort. After the operation 
we have left the patient entirely free, without any 
interference, for usually the space of ten days or a 
fortnight, and then have tried what sized bougie would 
pass. If no disintegrated tissue comes out upon the 
electrode, some sort of slough or eschar is thrown off at 
a later period — the next day, or a day or two after the 
operation, during the passage of urine. 

" Going back to the example we have already taken, 
if, after dissolving the stricture, it has been possible to 
pass a No. 5 electrode into the bladder, after the rest 
of a fortnight it is usually found that a No. 7 bougie 
can be passed. Should that be the limit of the in- 
creased calibre of the passage, a No. 9 electrode is 
taken, and the same operation repeated as before de- 
scribed, and so on after the interval of another fort- 
night, until the stricture is cured. The results of our 
investigations may be summed up as follows : — In the 
treatment of stricture of the urethra by electrolysis, 
there is usually no bleeding. If haemorrhage does 
occur, it is accidental, and usually shows that a too 
strong current or the wrong pole of the battery has 
been used. No anaesthetic is required. It is an assist- 
ance to the operation that the patient should remain 
conscious. The pain or discomfort produced is trifling. 
The patient can in the case of a slight stricture pursue 
his ordinary occupation during the period of treatment. 
In the majority of cases there is no contraction or return 
of the stricture. 


" Eschars formed by caustic alkalies are said to heal 
with less contraction than wounds produced in any 
other way, and electrolysis with the negative pole is a 
means of applying the destructive action caused by 
the caustic alkalies to parts difficult of access, and 
in a way which is impossible by any other method. 
But beyond this, the current appears to set up an ab- 
sorptive action around and within the dense cicatricial 
tissue which forms the stricture, so that it gradually 
disappears. This we have seen in several ways. After 
electrolysis has proceeded so that the electrode will pass 
into the bladder, it is found a fortnight later that a 
bougie of two sizes larger can be passed. Additional 
absorption must therefore have taken place in the in- 
terval. And again in penile strictures, where we have 
been able to feel the hard dense tissue of which they 
are formed, a few days after electrolysis we have 
noticed that this hardness has disappeared. 

This progressive improvement after the termination 
of treatment is very remarkable, and lends some colour 
to the belief that an actual absorption of fibrous tissue 
may be determined by the passage of the current. It 
has also been stated that the cure is more permanent 
than it is after ordinary dilatation. For reports of 
Mr. Bruce Clarke's cases, with their subsequent history, 
see Practitioner, 1886, and British Medical Joimial, 1890, 
vol. i., p. 942. 

In a letter written to me in 1892, Mr. Bruce Clarke 
stated that he still considered the results of electrolysis 
to be extremely good and permanent in cases of stric- 
ture. Of a patient who was treated by him in 1885^ 
he wrote : — " I saw him a few days ago, and passed a 
No. II with the greatest ease. No instrument has been 
passed since the operation, except by myself once or 


twice for purposes of diagnosis." The use of electricity 
for the treatment of stricture is under the disadvantage 
that it offers no special superiority over the other modes 
of treatment. These are sufficient for the ordinary 
needs of the cases, and the electrical method is there- 
fore superfluous. 

The electrical treatnient of any disease in order to 
justify its existence must offer results which are superior 
to those which can be had in other ways, and appar- 
ently surgeons do not find it necessary to use electro- 
lysis in stricture of the urethra because they can obtain 
the required results without it. 

260. Other strictures. — Electrolysis has been re- 
commended for stricture of the oesophagus by most 
writers on medical electricity. Stricture of the rectum 
can also be treated by means of electrodes shaped like 
rectal bougies, which are connected to the negative pole 
of the battery. A bougie is selected of a size rather 
larger than the stricture, to which it is applied firmly. 
A current of five or ten milliamperes is passed. After 
a variable time the stricture gives way, and the bougie 
passes through it. The time of each operation may be 
from ten minutes to half an hour. The operation is 
repeated with a larger instrument in ten days or a 
fortnight. No anaesthetic is required. 

261. Eustachian obstructJon. — In the Lancet for 
Nov., 1888, a paper on electrolysis of the Eustachian 
tube was pubhshed by Mr. Cumberbatch and Dr. W. E. 
Steavenson. The authors described their methods as 
follows : — " The instrument consists of a vulcanite 
Eustachian catheter and an electrical bougie (fig. 86), 
the bougie is made of a fine flexible copper cord about 
seven or eight inches long, insulated by vulcanite to 
within an eighth of an inch of its end. The ends are 



soldered into a nickel plated cap. The bougie is small 
enough to pass along the catheter, and exceeds it in 
length by about an inch. The handle end of the bougie 
is provided with a binding screw, to which the insulated 
copper wires are also attached, for the purpose of con- 
necting a rheophore from the battery. On this end of 
the bougie an inch is marked off divided into eighths. 
Each eighth of the inch passes into the catheter as one 
eighth protrudes at the other end. It is therefore pos- 
sible to tell, when the catheter is in the orifice of the 
Eustachian tube, how much of the bougie is in the 
canal. On the catheter there is a metal ring, or some 

Eustachian catheter electrode. 

other mark, to indicate the direction of its end w^hen it 
is being inserted. 

" Electrolysis of the Eustachian tube is performed 
in much the same way as the electrolysis of the other 
mucous passages. A pad connected with the positive 
pole of a battery is moistened and placed at the back of 
the patient's neck. The Eustachian catheter is then 
passed along the nostril and guided into the tube ; the 
bougie already attached to the negative pole of the 
battery, is passed along the catheter and Eustachian 
canal as far as it will go, until it meets an obstruction. 
The circuit is then closed. A galvanometer should be 
included in the circuit, and the current gradually in- 


creased up to four milliamperes. A frizzling noise will 
be heard by the patient in his head, and the operator, 
by approaching his ear to the catheter, may hear the 
crackling produced by the breaking of minute bubbles 
of gas. The electrolysis is kept up for four minutes, 
and usually before the expiration of that time, if it is 
possible that the obstruction can be removed, it will be 
found that the bougie can be pushed on for a small 
distance, sometimes for its full length. Generally on 
the first occasion the Eustachian tube is rather sensi- 
tive, but it seems to acquire toleration for the process, 
and at no time is so much discomfort experienced as 
might be expected. The operation has now been per- 
formed a large number of times without any unpleasant 
experiences, nor has the treatment caused any pain, 
either at the time or afterwards. 

" In favourable cases there is an immediate improve- 
ment in the hearing, as tested by the greater distance 
at which a watch can be heard after the passage of the 
instrument ; the distance at which it is heard may be 
doubled. In other cases the results are not so good, 
partly from the difficulty of reaching the Eustachian 
tube, and partly no doubt from other causes." This 
method has fallen into disuse. 

262. Lachrymal obstruction. — In a paper by Mr. 
Jessop and Dr. Steavenson,* an account is given of ten 
cases of lachrymal obstruction treated by electrolysis. 
The advantage of the method is again due to the ease 
with which the action can be confined to the exact 
parts needing treatment. The instrument used by them 
is a curved platinum probe. The operation is very 
simple ; the current required is small, two to four milli- 
amperes being sufficient, and the duration is thirty 
* BvH. Med. jfoiir., 1887, ii., p. 371. 


seconds. No anaesthetic is needed ; the probe must 
always be negative, the positive pole being the usual 
pad indifferent electrode. Two or three sittings suffice 
to produce cure of the obstruction. The cases related 
are confined to those in which the obstruction was at 
the punctum or in the canaliculus, and not in the sac 
itself. The operation is simpler than the slitting up of 
the canaliculus, and the improvement is permanent. 

263. Electrolysis for uterine fibroids. — Since the 
publication by Apostoli of his method of treating fibro- 
myoma, an itiimense amount of literature has been pro- 
duced on the subject. Much has been said both for and 
against Apostoli's"' treatment, and the enthusiasm which 
was at first shown in his favour by many writers, has 
to a large extent been followed by a reaction against it. 
There is no doubt, hov/ever, that electrolysis may hold 
a place in the treatment of fibroids, because it offers an 
alternative to the very serious operation of abdominal 
section, and in many cases it affords great relief to the 
symptoms of the patient, even if it does not effect a 
radical cure of the disease. What has been written 
above of electrolysis in stricture of the urethra applies 
also to the electrical treatment of fibroids, namely, that 
the electrical method competes with other surgical 
modes of treatment without offering any decided advan- 
tages, and in consequence it is neglected as being un- 
necessary, at least in this country. In the absence 
of any personal experience of the matter I propose 
here to give a short abstract of Dr. Carlet'sf original 

* See the medical journals, 1888, 1889, ^^^ publications by 
Drs. Steavenson, Bartholow, Keith, Massey, Engelmann and many 

f " Le traitement electrique des tumeurs fibreuses de ruterus,'* 
Dr. Lucien Carlet, Paris, 1884. 




paper, produced under the immediate direction of Dr. 

The early attempts at treating fibroids by electrolysis 
were done by Cutter, 1871. Routh and Althaus, 1873. 
Brachet, 1875. Semeleder, 1876. Everett, 1878. Aime 
Martin, 1879. Gallard, 1881. In 1882 Apostoli com- 
municated a paper to the Academic de Medecine, in 
which he described his method of procedure. He re- 
commended an internal positive electrode of platinum, 
and an abdominal electrode (negative) of moist china 
clay of large surface, and a continuous current of sixty 
to seventy milliamperes, for from five to fifteen minutes. 
In certain cases when the internal electrode could not 
be passed into the cavity of the uterus, he thrust it 
through the cervix into the tissue of the uterus instead. 
Sittings once or twice a week. The action of the cur- 
rent was to produce destruction of the uterine mucous 
membrane. The results were to reduce the size of the 
uterus, and to decrease the haemorrhage. The destruc- 
tion of the mucous membrane is followed by a healthy 
process of repair, by a process of involution, and by a 
cicatrisation which checks the metrorrhagia. 

Drs. Apostoli and Carlet arrange their account of the 
operation as follows : — 

1. The seat of the operation. — It must be intra-uterine, 
and the internal electrode must occupy the whole depth 
of the uterine cavity. To puncture the uterus from the 
abdomen is dangerous, for suppuration and peritonitis 
are likely to follow, adhesions are likely to be formed, 
and the uterine mucous membrane is not touched. 

2. The nature of the operation. — The positive pole is 
indicated for the internal electrode when haemorrhage 
is the chief symptom, the negative pole may be used 
when the fibroids are large, hard and subperitoneal, and 


when there is not much haemorrhage, for if anything it 
increases the tendency to bleeding. 

The current must be quite uniform, and must be 
raised and lowered very gradually, sudden interrup- 
tions with the large currents used are sufficient to give 
dangerous shocks. 

3. The strength of current. — The maximum strength 
which the patient can bear is to be employed ; w^hen 
the uterus is large, a greater strength is needed to pro- 
duce the same density of current (see § 112). Cauter- 
ization is easily obtained in an uterus of little length 
owing to the smaller surface for distribution of the 
current, but a much greater current is needed with a 
lengthened uterus, owing to its greater area. One 
hundred milliamperes is the mean strength used by 
Apostoli since 1883 (date of Dr. Carlet's paper, 1884), 
and this is generally well borne by the uterus. In hys- 
terical patients the current is not well borne, or rather 
a fit may threaten, unless the current is very cautiously 
increased. The operation must not be undertaken dur- 
ing acute perimetritis (or any other febrile condition). 

4. The duration of the operation. — The mean duration 
should be from five to ten minutes, according to the 
gravity of the case and the tolerance of the patient. 
When patients have to return home immediately after- 
wards, five minutes suffices in most cases. A strong 
current for a shorter time is better than a lesser current 
for a longer time. 

5. The numher of sittings. — An absolute cure with com- 
plete restoration to health (ad integrum), is and will ever 
be, beyond our medical resources. Our hope is that 
we may reduce the size of the tumour by one-half or 
one-third, and remove the symptoms. AMiether the 
tumours persist or not, the operator should persevere 


until the symptoms are relieved, and he ought not to 
be satisfied till this goal is reached. " He should 
depend on the general condition and statements of the 
patient, and not on what digital exploration reveals." 

Twenty or thirty sittings is the mean number, but 
many patients declare themselves cured after five to 
ten sittings. "If after great amelioration the patient 
desires to gain all she can from the treatment, it may 
be resumed, but the progress will be much more slow 
than at the commencement." 

6. Choice of time. — When pain and losses are not very 
great and other symptoms are not acute, choose the 
inter-menstrual period, but on the other hand, with 
serious symptoms making life miserable or endangering 
it, begin at once, even during severe bleeding. 

The intervals between sittings should be long enough 
for all pain or discharge produced by the previous ones 
to have ceased. The operation may be performed once 
a week, or even twice a week if the patient is able to 
keep her head or to remain very quiet. 

7. Technical details. — Before commencing, explain to 
the patient what is going to be done, make sure that 
the battery is in good order, and that all wires and 
connections are sound, disinfect the internal electrode, 
adapt the abdominal electrode of potter's clay carefully 
to the surface of the skin, first covering any little abra- 
sion or acne spot, however small, with a piece of oiled 
silk or guttapercha tissue. The patient must remove 
her stays and loosen all her skirts, and the abdomen 
must be quite bare. She must recline on her back on a 
couch or across the bed, the vagina must be thoroughly 
syringed out ; finally she must be assured that the 
operation will not be very painful, and that at the 
slightest sign from her the strength of current will be 


reduced, on the other hand she must be encouraged not 
to complain unnecessarily ; place the clay electrode on 
the abdomen, see that its margins do not touch the 
groins or pubes, attach the battery wire, then introduce 
the internal electrode with great care and gentleness. 
(This is the most difficult part of the operation, and it 
may be better to do it before applying the abdominal 
electrode). Make sure that it has passed to the full 
length of the uterus, examine to see that the vagina 
and vulva are perfectly shielded from metallic contacts, 
and encourage the patient to press with her palms upon 
the clay electrode, so as to keep it well applied. Do not 
commence the current till all pain from the introduction 
of the electrode has passed off. After the operation tell 
the woman that she will have pains for a few hours, and 
a slightly tinged discharge for a day or two. She must 
rest for two hours before going home, and must then lie 
down. Walking exercise is bad. Conjugal relations 
must be absolutely forbidden. 

Weak injections of Condy's fluid or carbolic lotion 
should be used once daily. 

The intra-uterine electrode has the shape of a sound, 
insulated except at its extremity, this part must be of 
platinum, and its length should be capable of adjust- 
ment to suit the length of the uterus. The insulation 
should reach sufficiently far to protect the cervix uteri 
as well as the vagina. Care must be taken that no 
bare metal touches the vulva, or the skin of the thighs, 
or a painful sore place will be produced. 

Dr. Apostoli's sound (fig. 87) was fitted with a sliding 
vulcanite sheath ; platinum pieces, either sharp or 
blunt, are screwed into the end of the shaft, and are 
chosen of a length to suit that of the uterine cavity. 
Subsequently Steavenson modified and improved the 


original pattern by making an electrode shaped like 
a hard rubber catheter with a platinum tip (fig. 88). 
The advantage of this shape is that the instrument 
is more flexible and more easily introduced into the 

Fig. 87. — Apostoli's uterine electrode and sheath. 

uterus, and the insulation part is not thicker than the 
rest, therefore, it can enter more easily into the cervix 
so as to protect that part. If this form of electrode be 
used it will be necessary to have a set with platinum 

Fig. £8 — Steavenson's electrode for fibro-myoma. 

ends of different lengths, whereas ApostoH's sound can 
be altered to suit each case by means of changing the 
platinum points. 

The electrodes with sharp points are made' for 


puncturing the uterus when the cervical canal cannot 
be reached. Puncture, however is now very rarely- 

An ordinary uterine sound made with a platinum end 
and fitted with a binding screw answers the purpose 
very well ; the stem can be insulated by a thin soft 
rubber tube slipped over it, leaving bare the appropriate 
length at the end. The edge of this soft tube will enter 
the cervical canal quite well, especially if it be painted 
over with a little collodion to fix it. The advantage is 
that such an instrument can be kept absolutely clean, a 
new piece of rubber being slipped on for each operation 
and a little vaseline smeared over to protect against any 
possible escape of current through minute holes in the 

The abdominal electrode is prepared by making up a 
putty like mass with the potter's clay and water, it is 
then spread out evenly on a piece of muslin in a layer 
half-an-inch thick. A metal plate with binding screw 
is embedded in its upper surface, and the muslin is 
folded over to enclose a round cake of the clay. It 
should measure about nine or ten inches in diameter. 

The preparation of this electrode is rather trouble- 
some, and it is heavy and rather messy for the patient^ 
but it adapts itself well to the surface of the abdomen 
and gives good results. Substitutes for it have been 
devised, such as large flat bags of bladder or dialysing 
parchment containing warm water or pads of wood 
pulp. These will also adapt themselves very closely. 
Metal plates covered with moistened flannel, or carbon 
in small lumps covered with flannel to form a cushion- 
have also been tried. 

A firm cake of gelatine also conducts very well, and 
is easily prepared by liquefying some gelatine and pour- 


ing it out into a small plate, a metal pad can be fixed to 
it when it has set, by laying it on the surface and pour- 
ing more gelatine over it. It is rather sticky and un- 
pleasant, however, as it has a tendency to melt at the 
temperature of the body. The addition of one or two 
per cent, of alum will prevent this, and will improve 
the pad, which is to be enclosed in muslin, and used 
exactly as the clay electrode. It is much more cleanly 
and agreeable. 

Bergonie and Boursier have published the notes of a 
hundred cases in which they carried out Apostoli's 
treatment for fibro- myoma, and they give the following 
summary of their views"' : — " The electric treatment of 
fibro-myoma is undoubtedly efficacious as a palliative 
method of treatment. When haemorrhage was the chief 
symptom complained of go per cent, were relieved. 
The general state of health was improved in 79 per 
cent., the symptom of pain was relieved in 50 per cent., 
while a decrease in the size of the tumour was observed 
in ten per cent, only." 

264. Extra-uterine fostation. — Attempts have been 
made to arrest the progress of extra-uterine foetation 
by electrical treatment, and cases which appear to have 
been successful have been recorded, most of them in 

In the St. Bartholomew's Hospital Reports, vol. xix., 
1883, Dr. Matthews Duncan and Dr. Mason published 
a paper on extra-uterine foetation, with an account of 
one case in which the pregnancy had lasted five months 
and the fcetal heart was audible. Electrolysis was 
practised on two occasions with a fortnight's interval. 
The current of forty cells was employed for six minutes, 
on the first occasion the poles were in the vagina and 

* Arch. d'Electricite medicale, 1893, 211. 



on the abdomen respectively ; on the second occasion 
two needles connected with the negative pole were 
thrust into the tumour while the positive was applied to 
the abdominal surface as before. 

The foetal heart was not arrested on either occasion. 
Other means of destroying the fcetus were then em- 
ployed, and the patient died of peritonitis a week after 
the second sitting ; post-mortem the foetus was found 
very considerably macerated, this was considered to 
have been due to the electrical treatment. 

Dr. Percy Boulton" has published a case of early 
(six or eight weeks) extra-uterine foetation, where elec- 
trolysis proved fatal from peritonitis, but there was no 
post-mortem examination to show what changes had 
been set up in the tumour. The case shows that 
electrolysis, even in the early months, is not free from 

Mr. Lawson Tait and other speakers at the Brighton 
meeting pointed out that very often tubal pregnancy 
may undergo spontaneous cure. It is very likely that 
some of those said to have been cured by induction coil 
shocks were really cases of this kind, because it is diffi- 
cult to see how a moderate induction current, diffused 
through the large sectional area of the abdomen, could 
exert any effect at all upon the tissues of a young foetus, 
though it might possibly produce some mechanical com- 
pression by setting up tonic contraction of the muscle 
fibres in the Fallopian tube round it. To slay even a 
small animal it is necessary to have very large currents, 
carefully concentrated upon a vital part. A foetus lying 
in the midst of the conducting tissues of the abdomen 
could only receive a small fraction of the comparatively 
small current yielded by a medical coil. 

* Brit. Med. yoiirnal, April, 1887. 


265. Cancer. — The destruction of cancerous tumours 
by electrolysis has been proposed. 

Although it is not likely that electrolytic treatment 
will do more than produce sloughing of parts of a 
cancer, yet it is sometimes useful, when nothing else 
can be done, because the pain of the cancer is often 
much diminished after electrolysis, as has been ob- 
served by Althaus. Cures of cancer by electrolysis will 
be found reported in many of the books on electrical 
treatment, but a close study will usually reveal some 
weak point in the history of the cases related. 





Cautery and Lighting Instruments. 


The galvano-cautery. Batteries for cautery purposes. Accumu- 
lators. Wires and leads. Lamps. Batteries for lamps. The 
use of electric light mains. Rheostats. The cystoscope. The 
panelectroscope. The electro-magnet. 

266. The galvanic cautery. — The forms of galvano- 
cautery in common use are numerous, but their plan of 
construction depends upon one general principle. The 
cauteries used for small operations consist of small 
loops of platinum wire mounted on straight or curved 
copper supports, which are insulated from each other, 
and then bound together to form a convenient stem 



Fig. Sg. — Platinum cautery points. 

(fig. 8g). These fit into a handle provided with bind- 
ing screws and a key for easily opening and closing the 
circuit. The platinum loops, having a relatively high 
resistance, become heated by the passage of the current.. 
The figure (fig. 90) shows an usual form of handle,. 


known as Schech's, which is made in two sizes. For 
most operations the shorter handles are more convenient 
than the large size, which is too unwieldy for delicate 

Fig. go — Schech's handle. 

For fine work a very nice handle is made in the 
shape of a metal pencil case, (fig. gi). Connection is 
made by a twin wire with a plug which fits a socket at 
the end of the handle, the switch is a rmg of metal 
sliding over a piece of ivory. This form of cautery 

Fig. gi. — Cautery handle. 

handle is much the most convenient for small work, 
and whenever burners mounted on long stems are not 
required. Its length is five inches. 

The current which heats the platinum points heats 
the cautery mounts as well, in a less degree, the cur- 
rent, therefore, should only be left on when the . cautery 
is in actual use. The supports are insulated by a thick 
waxed thread twisted round them in racking turns, 
which keeps them from touching, although binding 
them together, and forms a [sufficient means of insula- 
tion, except when they become overheated. 


Besides the simple platinum loops, cutting instru- 
ments of various shapes are made by hammering the 
platinum flat or by bending it in various ways. Where 
a larger incandescent surface is required, a loop or 
spiral of platinum supported in grooves on a porcelain 
mount is made, the porcelain then becomes heated to 
redness as well as the platinum (see fig. 92). Different 
thicknesses of platinum wire are used, and accordingly 
the current required varies greatly in different cau- 

Sometimes a long loop of wire is used as an ecraseur, 
being adapted cold to the part to be removed, and then 
heated, and a screw can be mounted on the handle 

Fig. 92. — Cautery for larger incandescent surface. 

figured above for gradually drawing up the wire loop- 
when it is hot. It is as well to mention that the tem- 
perature of a cautery must not be allowed to rise above 
dull redness. At a white heat the cauterising action 
is so rapid that searing of the surface does not take 
place, and haemorrhage may follow as profusely as 
after division of the tissues by a knife. A large number 
of modified forms of cautery and mount will be found 
in the instrument makers' catalogues. The resistance 
of the cauteries just described may vary from -025 to 
•04 ohm. 

The current required to bring the platinum loops to 
redness varies between eight or ten amperes for the 
smaller, to upwards of twenty for the larger ones. 

Still larger currents are required for a few cauteries, 
which have been constructed for special purposes. 


In the prostatic cautery of Prof. Bottini*'-' the part 
to be heated consists of two strips of platinum, each 
20 mm. X 8 mm., which he side by side in the concav- 
ity near the beak of an instrument, which is shaped Uke 
a vesical sound. The current passes along one strip 
and returns by the other. The large mass of the 
platinum makes the resistance of the part to be heated 
remarkably low, about -0005 ohm, and consequently an 
immense current, amounting to fifty amperes, is required 
to raise it to a red heat. Such a current as this taxes 
any portable battery to the utmost. This instrument is 
used for the radical cure of the symptoms caused by 
enlarged prostate, and its use has been advocated in 
this country by Mr. Bruce Clarke, f who has employed 
it successfully on several occasions. 

267. Cautery batteries. — The batteries of small 
cells which are used in medical treatment are arranged 
for high electromotive forces with the minimum of 
weight, and their internal resistance is of little import- 
ance. For cautery purposes the conditions are quite 
different, and the small medical cells are therefore 
unsuitable. Large bichromate cells have been much 
used for cautery purposes, but they are rather trouble- 
some to maintain, although they may be made to yield 
a large current for a brief period. Fig. 93 shows a 
form of this battery which is strong and good, and may 
be easily arranged as a two cell battery with pairs of 
cells in parallel for cautery purposes, or as a four cell 
battery for electric lamps (see § 270). In places where 
storage cells cannot be used this form of cell must be 
had recourse to. 

* Brii. Med. yotirnal, iSgi, vol. i., p. 1121. Description and 

t Proceedings of the Medico-Chirurgical Society, Jan., 1892. 



Fig. 93. — Bichromate battery for electric lamps and galvano-cautery. 

By far the most convenient form of battery for cautery 
and lamp work is an accumulator. An accumulator or 
secondary battery gives a steady current, its internal 



resistance is very small, its storage capacity is large, 
it can be recharged when exhausted from a dynamo 
or from the direct current mains (§ 69) and it will 
keep in good order for several years if given proper 
attention. With care in use (§ 59) they are perfectly 
trustworthy. They are heavy, but not more so than any 

Fig. 94. — Accumulator for lamps and cauteries. 

other cautery battery. The Electrical Power Storage 
Company prepare small accumulators for medical pur- 
poses. These will heat all ordinary cauteries well for 
the brief periods during which the cautery is required ; 
if much heavy work is required to be done a larger size 
is better. 



The most convenient outfit for cautery and surgical 
lamps is a four-celled accumulator. It may be fitted 
with a switch for rearranging the cells in two pairs in 
parallel, and can then be used either as a two-cell 
accumulator of double cells for cautery purposes, or 
as a four-celled one for lamps taking up to eight volts. 
There is no special advantage in this except for heavy 

Fig. 95. — Accumulator for lamps and cauteries. 

cautery work, and the extra connections are sometimes 
troublesome. Figure 95 shows such an apparatus, which 
is constructed for surgical purposes. It weighs fifteen 
pounds, and is provided with two resistances, one for 
lamp and one for cautery use. The connections are so 
arranged that the lamp resistance is in series with the 
lamp terminals and the cautery resistance with the 


cautery terminals. It measures 7x4x5 inches, and 
is to be obtained from Mr. Leslie Miller, 93 Hatton 
Garden, E.G. The Lithanode Gompany also make a 
good accumulator battery for lamp and cautery work 

(%• 95)- 

268. Electric light mains.— In § 66 the use of 

electric lighting mains for medical purposes was dis- 
cussed. When they are to be employed for small 
surgical lamps or for cauteries, certain points are im- 
portant, and will therefore now be considered. With 
the alternate current supply a transformer should always 
be used, and it should permit of adjustment to suit the 
exact pressure needed for the lamp or cautery to be 
used. This can be done by a proper make of trans- 
former, or by means of an accessory resistance. There 
is no difficulty in obtaining what is required, as small 
transformers for light and cautery purposes are made 
specially (§ 70). 

On direct current circuits the mains may be used to 
charge an accumulator and this can be subsequently 
used for the lamp or cautery. This has the advantage 
that the accumulator can be taken to a patient's house 
to be used. As this is necessary from time to time an 
accumulator must be had and then the fitting of an 
apparatus for use direct from the mains is not required, 
and the expense of it may, therefore, be saved with 
advantage. The charging is a simple matter, and has 
been already dealt with (§ 69). For small lamps an 
adjustable resistance direct on these mains is compara- 
tively unobjectionable. When it is proposed to heat 
a cautery from the mains direct, the matter becomes 
much more difficult to carry out. A cautery requires 
ten amperes or more to bring it to redness, and a cur- 
rent of this magnitude is quite sufficient to maintain 


an arc if from any cause the platinum of the cautery 
should break or fuse during its use. The unexpected 
establishment of an arc during cauterisation of a patient 
might have serious consequences. 

The risk of such an accident can only be avoided by 
having two parallel circuits from the positive to the 
negative main, one to carry the cautery and the other 
to act as a bye-pass in case of accidental fusing or 
fracture of the cautery wire. No arc need then be 
feared, but the apparatus expends energy at the rate of 
about two-horse power while it is in action, and special 
main wires and fuses are required to carry the current. 
As each branch may have to carry upwards of ten 




Fig. 96. — Arrangement of wires for cautery on continuous current mains. 

amperes when the cautery is at work, they must be 
constructed in a substantial manner to stand that mag- 
nitude of current. 

A properly designed apparatus for this purpose is in 
use at some of the London hospitals, and works well. 
Mr. INIiller, who designed it, writes as follows: — "The 
apparatus we have fixed up has been in use for over a 
year and gives satisfaction. We see no other way of 
doing what is wanted, and for hospital use it is perhaps 
better than accumulators. A red lamp burns whenever 
the current flows, so that there is no excuse for wasting 

A diagram of the connections is as follows : — A on 
the positive main represents a strongly made resistance 
of about five ohms. B is a red lamp. C switch. D 


wires to cautery. E bye-pass, its exact resistance 
being varied by the moving arm, which is used as 
the regulator (fig. 96). 

With this apparatus a current of about twenty 
amperes traverses the circuit when the switch is on. 
At FF the current divides, passing either through a 
resistance E, or through both E and the cautery D. 
The amount going by each route is adjusted by the 
moving arm, which can travel along E. 

In this way the tendency to an arc is got rid of, and 
there is very much less sparking and burning at the 
contact in the handle of the cautery. Mr. Schall also 
supplies a similar apparatus. 

269. Conductors. — It is important to use thick 
copper wire conductors for a cautery heated from a 
battery or an accumulator because the resistance of 
the whole circuit being very low, that of the conductors 
becomes an important fraction of it, and may determine 
whether the cautery will be properly heated or not. 

It may be useful to give an example here of the 
calculations to be made in arranging the apparatus 
for heating a cautery. Suppose that a cautery having 
a resistance of -04 ohm and requiring a current of 20 
amperes is to be heated, and that the battery power 
available consists of two accumulator cells in series, 
each with an electromotive force of two volts, the 
internal resistance of each cell being 'oi ohm. 

To obtain a current of twenty amperes from four 
volts the total resistance in circuit may amount to -2 
ohm. If proper leads are used, their resistance will be 
•0014 ohm per metre. We will suppose each wire to be 
1-5 metres in length, their total resistance will then be 
•0042 ohm. The necessary resistance in circuit in this 
case (resistance of battery, of leads, and of cautery) 


therefore amount to -02 + -0042 + '04 = -0642, or say 
•065 ohm. This leaves a margin for faulty contacts and 
for rheostat of -135 ohm, and the cautery would be 
adequately and easily heated. For the kind of rheostat 
used with cautery see figures 94 and 95. 

But, now suppose that the leads are of a size having a 
resistance of -04 ohm per metre. This will give a total 
resistance in circuit of -02 + -12 + -04 = -18 ohm, 
leaving a bare margin of '02 ohm for faulty contacts. 
This would be insufficient, as there are several points 
of contact and a small degree of oxidation or tarnishing 
at any one of them would prevent the cautery from 
heating, add to which there would in all probability be 
a considerable amount of heating in the leads, which 
would certainly increase their resistance, and might 
destroy their insulation. These examples show the 
importance of using conducting wires with plenty of 
copper in them, and of keeping all contacts and binding 
screws scrupulously clean and bright. A rheostat must 
always be included in the circuit when a cautery is to 
he heated, if this precaution is neglected, there will 
be much trouble from over-heating and fusing of the 
platinum loops. 

270. Surgical lamps. — Small incandescent lamps 
have been adapted to laryngoscopes, ophthalmoscopes. 

Fig. 97.— Laryngoscope with electric lamp 

vaginal specula and other instruments (fig. 97 and 98). 
They are not used very universally, because in many 
cases the maintenance of the battery is troublesome, and 
because other sources of illumination are sufficient. 



Lamps are also made to fix to an operator's head 
for giving a beam of light during 
operations. A very good small lamp 
is made by Beddoe, of Nine Elms 
Lane, S.W., and was described and 
figured in British Medical Journal, 
Dec, 1892, by Mr. Washington 
Isaacs. It throws a small parallel 
beam, and is nicely made. It weighs 
only half-an-ounce. 

These small lamps are of about one 
candle power and vary a good deal 
in their resistance (5-20 ohms), and 
therefore the electromotive force re- 
quired to bring them to incandescence 
varies also. If the filament is slender, 
or if it is long, their resistance is 
high, if it is short or thick, their re- 
sistance is less high. A long slender 
filament may require eight or ten volts 
to light it properly, while a shorter 
one will glow with six volts. The rate 
of consumption of energy by an incan- 
descent lamp is about four Watts per 
candle. Thus if a ten volt lamp ab- 
sorbs '4 of an ampere, a six volt lamp 
would require -7 ampere to give the 
same light. When the current is sup- 
plied from a portable battery it is best 
to use the higher voltage lamp for the sake of the 
advantage of having to provide a smaller current, 400 
milliamperes, -4 ampere being more within the range of 
a portable battery than 700 milliamperes, and the battery 
will therefore run down less rapidly. On the other 

Fig. 98.— Ophthalmo- 
scope with electric 


hand a greater number of cells will be required to pro- 
vide the higher voltage. It would be a convenience if 
all small surgical lamps were made for one and the same 
voltage. As the four cell accumulator of eight volts is 
the type of battery most generally useful lamps should 
be chosen as far as possible to incandesce brightly with 
this electromotive force. 

Among primary batteries useful for lighting small 
lamps the bichromate cell is convenient if no means 
of recharging accumulators are available. Dry cells 
may be used for this purpose, but do not keep well nor 
last long if used much for lamps. Six dry cells fitted 
m a plain oak box are supplied by Mr. Schall with a 
simple form of rheostat, and they may be trusted for a 
fair number of examinations. It should be borne in 
mind that dry cells gradually fail as they get old, 
w^hether they be used or not. From three to six 
months may be taken as the duration of usefulness 
with dry cells. 

If accumulators are used, small ones may be had for 
the sake of portability. Small accumulators are put up 
by several electrical instrument makers and serve well 
for surgical lamps (see fig. 15 and 16). The small sizes 
naturally require recharging more often than the large 
ones, but this is not an objection, because all accumu- 
lators are better for being recharged at least once a 
month, and the capacity of the small cells is sufficient 
for lighting a cystoscope or similar lamp for several 
hours. If the small accumulators can be recharged at 
home from the mains without trouble they are extremely 
convenient, but this convenience is mainly lost if they 
have to be sent away every time to be recharged. 

271. Rheostats. — We have already said that the 
lamps vary a good deal in their resistance, and a 


regulating resistance in the circuit is necessary for 
compensating for these variations, as without it some 
lamps would be overheated and would quickly be 
destroyed. Rheostats of convenient size are supplied 
with many of the types of portable accumulator now 
in the market. The resistance required for regulating 
the lamps need not be more than about six or eight 
ohms. As the current to be carried is only about half 
an ampere in a well made lamp the resistance is easily 
made of a few turns of fine German silver wire. Rheo- 
stats are equally important for cauteries, but there they 
have to carry large currents and must be made of thick 
wire ; however, their total resistance need not be so 
great, for a variable resistance of half an ohm is suffi- 
cient to modify very greatly the current in a cautery 

272. The cystoscope. — This is an instrument for 
examining the mucous membrane of the bladder, and 
it is perhaps the most important and useful of all the 
electric lamp instruments, because it affords information 
of the greatest value which cannot be obtained without 
it. The cystoscope (figs. 99 and 100) consists of a 
beaked sound, in which there is a telescopic arrange- 
ment by which the surface of the bladder is viewed 
through a small window of rock crystal. A lamp L is 
enclosed in the beak of the instrument and throws its 
light through another window CF (fig. 100), upon that 
part of the bladder wall which is in the field of view 
of the telescope. 5 is a screw for making contact, the 
wires are fastened at CD (fig. 99) For examining the 
upper part of the bladder a separate instrument with a 
small reflecting prism is used. A certain amount of 
practice is required to use the cystoscope properly, and 
to recognise the appearances of the mucous membrane 




oi the bladder in health and 

its various morbid 

Fig. 100. — Arrangement of lamp in 

L. Lamp. CC. Attachment to instru- 
ment. CF. Window in cap of instrument. 

Fig. 99.— Cystoscope. 

conditions. With the dummy bladder (fig. loi) the 
necessary skill can be quickly picked up. For a full 



account of the instrument and mode of using it, see 
Mr. Hurry Fenwick's book on " The Electrical Illu- 
mination of the Bladder and the Urethra. '"•= An anaes- 
thetic is not absolutely necessary for a cystoscopic 
examination, but it is more convenient to employ one, 
though cocaine may be made to do. The bladder must 

Fig. ioi.— Cystoscope and dummy. 

contain six or eight ounces of clear urine or clear water 
if a proper view of its walls is to be obtained. 

If the fluid present be even slightly turbid, the view 
is very much obscured ; and the bladder must be 
washed out with warm boracic lotion until the fluid 
which returns is absolutely clear. If too little fluid be 
present in the bladder, the beak of the instrument with 
* London, J. & A. Churchill. 

II 2 


the lamp is likely to become buried in the folds of 
the mucous membrane, and there will be no light. 
Moreover, in that case the mucous membrane may be 

When the bladder contains eight ounces of clear fluid 
the end of the cystoscope lies free in the cavity, and the 
lamp is kept cool by the circulation of the water. The 
instrument must be pushed well home into the bladder 
and kept there ; if it be allowed to work out at all, the 
beak may become engaged in the prostate, and then 
nothing will be seen and the prostate may be burned. 
The heat of the lamp is unimportant when it is sur- 
rounded by a volume of water, but when the lamp lies 
close against the mucous membrane there is no circula- 
tion of fluid round it, and it gradually grows hot and 
will burn if held too long in one place. 

273. The panelectroscope. — An universal lighting 
apparatus has been introduced by Leiter, of Vienna, 
under this name. It consists of a lantern with a handle 
and mirror ; the light from a small incandescent lamp 
is projected by the mirror along a tube, which is 
inserted into the part to be examined. Tubes of 
various sizes are adapted to the instrument. It is 
especially useful for endoscopy of the urethra, but is 
also arranged for examining the ear, the pharynx, the 
stomach, &c. For a full account of the method of 
using it for examining the urethra, and of the appear- 
ances of the different morbid states, see Mr. Hurry 
Fenwick's book already quoted in the last paragraph. 

Another convenient lamp for abdominal surgery is 
shown in fig. 103. It is designed in such a way as to 
be kept clean and aseptic without any difficulty. It 
may be left in the antiseptic solution until required for 
use. The attachment to the leads is by a double 



socket fitting, one wire making contact with the peri- 
phery of the tube which carries the lamp, and the other 
with an insulated lead which passes down the centre. 

Fig. 102. — Panelectroscope (handle not shown). 

The enclosing tube of glass prevents any burning of the 
tissues with which it might come in contact during an 

The exploration of the antrum of Highmore by means 


Fig. 103. — Lamp for abdominal operations. 

of a lamp placed in the mouth, has excited a consider- 
able amount of interest since the publication by Heryng" 

* Berlin. Klin. Wochens.,l>^o. 25, Sept. 2, 1889. " L'eclairage 
electrique de I'antre de Highmore dans le cas d'empyeme." See 
also " De I'empyeme latent de I'antre de Highmore; Dr. Jeanty." 
Bordeaux, i8gi, Feret et fils. ■ 




of his paper on the subject. The patient must be in a 
perfectly darkened room, the lamp is 
introduced into his mouth, and the 
lips 'are closed over its stem ; when 
the current is then turned on the face 
becomes lighted up by a red glow. 
If one antrum contain pus a dark 
shadow is seen on the corresponding 
side, which is most perceptible just 
below the eye. A properly arranged 
lamp is made for the purpose by Mr. 
Schall. It should have an illuminat- 
ing power of three or four candles. 

The same method of trans-illumina- 
tion has been employed for detecting 
deep-seated pus in other parts of the 
body ; it has even been said that by 

means of a light in the bladder the 
contours of the abdominal viscera 
have been traced out. The diffusion 
of the light through the tissues, how- 
ever, does not give much in the way 
of detail. 

274. The electro -magnet. — In 
certain cases this instrument is very 
valuable for the removal of fragments 
of iron or steel from the various parts 
of the body, especially from the eye. 
Permanent magnets can also be 
used. Mr. Simeon Snell"^ has made 
large use of the electro-magnet, and 
has had great success with it. If 

The Electro-magnet in Ophthalmic Surgery," and Brit. Med. 

Fig. 104. — Electro 

your., November, 1SS3. 


the particle of iron be very small, or if it be fixed at 
all firmly in the tissues a magnet is not likely to remove 
it. But if the piece of metal be larger, and if it be 
lying loose, as, for example, in the interior of the eye, 
it may be withdrawn most successfully by a magnet 
introduced through a small incision. 

One form of the instrument is figured here (fig. 104), 
several interchangeable pole pieces of different shapes 
and sizes are generally supplied, the most suitable one 
for each case can be screwed on at A as required. A 
few cells of any battery will suffice to excite the electro- 
magnet. It is sometimes useful to magnetise it by 
closing the current circuit after it has been placed in 
position near to the piece of iron. This is done in the 
instrument here figured by pressing down the small 
projecting slip of metal seen on the surface of the coils. 
The sudden magnetization then tends to jerk the piece 
of metal away from its bed. In the same way an 
electro-magnet excited by an alternating current has 
been found useful. The alternate magnetisation and 
de-magnetisation set the steel particle vibrating, and 
promote its dislodgment. In firmer tissues it is not 
always possible to extract it by an electro-magnet, for 
naturally it cannot hold the particle as firmly as it 
would be held by any kind of forceps. A large number 
of communications on the electro-magnet in surgery 
will be found in the medical journals 



The Rontgen Rays/" 

The Crookes' tube. The sources of electricity. The static machine. 
Management of coils. Screen work. Photography. Localisa- 
tion of foreign bodies. Diseases of the heart and lungs. 

275. The discovery of Rontgen or X rays followed 
upon the work of Lenard, who, experimenting with 
Crookes' tubes, had found that he was able to obtain 
manifestations outside the tube. Until his time the 
attention of observers had been so fixed upon the 
phenomena taking place inside the tube that effects 
outside the tube had not been looked for. Lenard 
found that a Crookes' tube, when excited, emitted 
radiations w^hich could be recognised in the open air 
outside and around the tube, and that these radiations 
had the power of exciting phosphorescence in suitable 
bodies, and of acting upon sensitive photographic plates ; 
and, in particular, that this action on photographic plates 
could take place through the sides of a cardboard box, 
which had little effect in stopping the "kathode" rays. 
With this to work upon, Professor Rontgen drew the im- 
portant deduction that a Crookes' tube could be made to 

* This chapter is not intended to give more than an outline of the 
methods and principles concerned in X ray work. The subject is 
too large to be dealt with in a few pages. Those who wish to make 
a study of the subject will find an admirable book upon it in " The 
Rontgen Rays in Medical Work," by David Walsh, 2nd edition 
London, 1899. Bailliere, Tindall and Cox. 


give out rays which penetrated opaque bodies in propor- 
tion to their density, and could be made to throw shadows 
on a photographic plate, which when developed would 
give an image showing any inequalities of density in the 
object photographed. It was a natural step from this 
to make a photograph of the hand showing the bones : 
and upon this, again, the very important development 
of X ray work in surgical and medical practice has 
been erected. Professor Rontgen's work was much 
more than this, for he distinguished between Lenard's 
^'kathode rays" and his own or X rays and indeed 
worked out the whole of his subject so thoroughly as to 
leave but little for subsequent investigators to discover. 

The essential parts for the production of X rays are 
two in number ; first, a Crookes' tube, suitably modi- 
fied ; and, secondly, an electrical apparatus capable of 
supplying currents at the necessary electro-motive 
force to excite the tube to action. 

276. The tube. — A Crookes' tube is a vacuum tube 
in which the exhaustion of the air has been pushed to 
its utmost limits. , It differs from an ordinary vacuum 
tube in the phenomena which it exhibits when elec- 
trically excited. Whereas an ordinary vacuum tube 
appears filled with glowing gas during the discharge 
of electricity through it, the Crookes' tube shows little 
or none of this appearance ; while instead of it a 
peculiar phosphorescence of the walls of the tube, 
previously hardly apparent, is the most conspicuous 
feature. The vacuum in a Crookes' tube is about one- 
millionth of the pressure of the atmosphere. The phos- 
phorescence in such a tube is caused by a bombard- 
ment of its walls by gaseous molecules propelled with 
enormous velocity from the kathode. And it was shown 
by Crookes that these molecules are propelled in straight 


lines from the surface or surfaces of the cathode, and 
continue to travel in straight lines until they strike an 
obstacle, such as the walls of the tube itself, or of any 
body intentionally enclosed in the body of the tube and 
in the path of their movements. The X rays are pro- 
duced when the bombardment strikes the solid object. 
Any tube exhibiting this phosphorescence of its walls 
is emitting X rays from the phosphorescent parts and 
the earliest tubes used in X ray work were of this kind. 
The objection to them was that X rays were emitted 
from a large portion of their surface, and therefore did 
not give pictures so sharp in focus, as if the rays had 
been emitted from a small surface. The greatest 
improvement in the construction of the special Crookes' 
tube for X ray work was effected by Mr. Jackson, of 
King's College, London, who contrived a tube with a 
piece of platinum fixed in such a position as to receive 
the concentrated bombardment from the kathode. The 
X rays in his form of tube are emitted from a small 
portion of the surface of the platinum instead of being 
emitted from a large portion of the glass wall of the 
tube. The kathode usually takes the form of a cup- 
shaped disc of aluminium ; and the platinum target or 
anti-cathode devised by Mr. Jackson is placed nearly at 
the focus of the cathode. Owing to the cup-shape of 
the cathode, the bombardment converges to a point at 
or near the surface of the anti-kathode. The object of 
the high vacuum is to diminish the number of molecules 
of gas remaining in the tube to such a degree that those 
which are left shall be free to move in straight lines, 
without obstruction or retardation from collisions with 
other molecules. Thus, the higher the vacuum the 
more freely can the repelled molecules travel until they 
strike the anti-kathode. In tubes of low vacuum their 



movement would be arrested before they could travel 
the required distance. The figure shows a form of the 
Jackson tube which is now most widely used. In it one 
may see the cup-shaped kathode, the obliquely placed 
target or anti-kathode of platinum, and a third terminal 
which is usually connected to the anti-kathode outside 
the tube, and which acts as a regulator, making the 
behaviour of the tube more constant. The probable 
action of the third pole is to serve as a means of reliev- 
ing the molecules of their electrical charges, thus setting 
them free to return to the cathode, whence they are 

Fig. 105. — X ray tube. A. Kathode. B. Anti-kathode. C. Anode or third 

again repelled. It has been noticed that during use a 
vacuum tube becomes gradually more and more difficult 
to excite ; and many tubes have had to be returned to 
the maker to correct this fault, owing to their vacuum 
having become so high as to resist the full power of the 
coil used for exciting them. Tubes with a third pole 
increase in resistance much more slowly. The actual 
degree of vacuum which is best in a tube will depend 
upon the electromotive force which is available for 
exciting it. Thus, a tube which is too high for a coil of 
medium size will serve admirably for another of greater 


strength. There are, therefore, fairly wide limits of 
vacuum within which X ray effects can be produced. 
The higher the vacuum in the tube, the stronger is the 
electromotive force necessary to work it, but the better 
is the quality of the X ray radiance emitted. Or rather, 
one may say, the greater is the power of penetration of 
the X ray radiance emitted. The words "soft" and 
"hard" are commonly used to designate tubes of lower 
and of higher resistance respectively. Thus, we may 
say that a tube which is soft when new will gradually 
become harder and harder with use, and will, therefore, 
become more suitable for photographing the thicker 
parts of the body and less suitable for photographing 
the thin ones. If too "hard" its rays may have too 
high a penetration, and will then traverse bones almost 
as freely as soft tissues and will give a photograph 
in which the contrasts between the bones and the 
soft tissues are insufficiently marked. Dr. Mackenzie 
Davidson has introduced a further improvement into 
the X ray tube. The improvement consists in using 
a piece of solid osmium to receive the bombardment 
from the cathode. Platinum is too soft a metal to 
stand the full effects of a sustained molecular bombard- 
ment concentrated upon one point on its surface ; and 
on this account in ordinary X ray tubes the platinum 
anti-cathode is intentionally placed at a little distance 
beyond the actual focus of the bombardment. When 
osmium is used, its hardness and infusibility make it 
possible to place it in the exact focus of the discharge. 
The X rays emitted by such a tube are therefore 
emitted from a smaller radiant point, and throw 
sharper images than the ordinary tubes. 

277. The source of electricity. — Very high elec- 
tromotive forces are required to excite an X ray tube, 


and the instruments in use for obtaining the high 
electromotive forces needed are (i) the induction coil, 
(2) the statical machine, (3) the Tesla coil. Of these 
the induction coil is the most generally useful, and most 
of the X ray work done in this country is performed by 
means of coils. The statical machine also has advan- 
tages which will be considered immediately, but it has 
the one great disadvantage of not being portable except 
in the smaller sizes, and these have not yet shown 
themselves equal to the coil. It is therefore not pos- 
sible to use it for cases requiring the application of 
X rays at the bed-side. The Tesla coil affords a con- 
venient means of obtaining currents of high potential, 
wherever alternating electric light mains can be tapped, 
but it has the disadvantage of breaking the tubes very 
rapidly. It is also objected to it that it is bad because 
it gives an alternating current as compared with the 
unidirectional current of the induction coil. This, 
however, is not the real objection to it. The real 
objection is that its discharges are high frequency 
discharges, and high frequency discharges behave in 
a very peculiar manner inside a vacuum tube. Strange 
to say, it is very difficult to confine them to the leading- 
in wire so as to deliver them where wanted at the 
surface of the kathode. They seem to prefer to escape 
into the vacuum tube from the stem or support of the 
cathode, as though anxious to pass from the metallic 
conductor into the gaseous one. If the stem be pro- 
tected by a glass tube, as is usual, they will quickly 
puncture this, and opposite the point at which they so 
puncture the glass stem, they quickly heat the wall of 
the tube and cause it to crack. On this account the 
use of the Tesla coil is rendered so costly and trouble- 
some that it is now almost totally neglected in X ray 


work. Induction coils are generally classified in terms 
of the length of the spark which they are capable of 
giving. Thus a six-inch coil is one which can give a 
spark of six inches in length. The proper size for good 
practical X ray work is a ten-inch or a twelve-inch 
coil. Good work may be done with a six-inch coil, and 
X ray photographs may be taken with a coil giving only 
a two-inch spark. But in practical work it is found 
that the more powerful the coil the better will be the 
pictures, and the shorter will be the necessary period 
of the exposure. From what has been said of the 
difference between soft and hard tubes, it will follow 
that a tube which is too hard to be excited at all by a 
four-inch coil, may behave as a good tube for a ten-inch 
or twelve-inch coil. 

With a twelve-inch coil the tubes remain longer in 
condition than with smaller coils. The increase of re- 
sistance of the tube or its ^'hardness" which comes from 
use comes more slowly with the larger coils. It appears 
as though the electrical stresses set up at these high 
electromotive forces are sufficient to break down the 
resistance of almost any tube ; certainly, since the 
general use of twelve-inch rather than six-inch coils the 
need for re-exhaustion of tubes seems to be very con- 
siderably diminished. At St. Bartholomew's Hospital 
I have noticed this in a very marked way. At present 
we hardly ever find that tubes have become too high 
for work. When we used a six-inch coil our tubes 
aged much more quickly. 

The statical machine. — The special advantages of the 
statical machine consist in its simplicity. Whereas a 
coil requires accumulators to drive it — and the recharg- 
ing of these accumulators may be a matter of great 
difficulty in remote or country places — the statical 


machine is a self-contained electrical apparatus capable 
of generating the necessary electromotive force by 
itself whenever its handle is turned. It also gives a 
steady radiation with X ray tubes, which is much less 
tiring to the eye with screen work than the flickering 
light given by the interrupted discharges of the induc- 
tion coil. In fact, for screen work the statical machine 
is admirable. For photography it is as good as the 
induction coil, though perhaps no better, and wherever 
an apparatus is required which need not be transported 
to the bed-side of the patient, the statical machine has 
much to recommend it. It has been said that with the 
static machine longer exposures are needed than is the 
case with large coils, but the statement needs con- 

278. The coil. — The working of the large coils used 
in X ray work requires a little experience, particularly 
in the management of the contact breaker. The con- 
tact breakers of large coils may either be the ordinary 
vibrating hammer, like those used in small medical 
induction coils, or the interruptions in the primary 
circuit may be produced by some mechanical device 
separate from the coil, or by the peculiar electrolytic 
arrangement known as the Wehnelt interrupter. The 
ordinary hammer answers very well for coils up to six 
inches ; even with ten and twelve inch coils a large 
amount of the work done with X rays is carried on with 
the vibrating hammer fitted with a " tension screw" for 
purposes of regulation. If a few experiments are made 
with a long spark induction coil, it will soon be found 
that small adjustments of the tension screw of the con- 
tact breaker produce very great effects in the length of 
spark which the apparatus can be made to give out. 
Thus, with the contact breaker spring quite loose, a 



six-inch coil will only give sparks of one or two inches, 
and the sparks can be made longer and longer by 

?^ o 

increasing the tension of the screw of the contact 
breaker. The management of the contact breaker 
therefore consists in adjusting the tension of its spring 


to suit the tube which is being used and the part which 
is being photographed. For thick portions of the body 
and hard tubes it may be advantageous to screw up the 
contact breaker so tightly that the fuU strength of the 
battery is necessary to make it work. Under these 
conditions the primary current is only broken when the 
full current is flowing in the primary and the full 
magnetising effect upon the iron core is developed. 
A sudden break of current at this moment gives the 
maximum effect of which the coil is capable. When 
working with a tightened tension spring it is necessary to 
stand by the apparatus while it is at work lest the 
platinum points of the vibrator may stick and the rush 
of current which follows may damage either the accu- 
mulators or the coil. It is also necessary to take care 
of the platinum contacts of the contact-breaker. They 
burn away gradually and their surfaces become uneven 
and need to be filed from time to time, to give them 
flat, smooth, clean surfaces, if the coil is to work 
satisfactorily. New platinum points must be fitted 
when the old ones are worn away. 

When the coil has been made to work satisfactorily 
the tube may be connected to it and the current turned 
on. The tube is held in a wooden clamp of suitable 
size and shape, many patterns of tube holder are made. 
When set in action, the phosphorescence of the glass is 
the indication which shows whether the tube is working 
properly, and the correct direction of the discharge 
through the tube may be obtained by means of a 
commutator in the primary circuit of the coil. When 
the kathode of the tube is properly attached to the 
negative pole of the coil, the phosphorescence will 
occupy one hemisphere only of the tube, the hemisphere 
which fronts the face of the anti-kathode which is turned 



towards the kathode. If the connections are wrong, 
the phosphorescence inside the tube is not thus sharply 
confined to its proper part, but is irregular and ill- 
defined on all parts of the tube. If the room is dark- 
ened, a phosphorescent screen held in front of the 
anti-kathode will shine brightly, and the hand placed 
between it and the tube will throw a shadow in which 
the bones are quite easy to perceive. The phosphor- 
escent screens are usually ten inches by eight inches in 
size. Larger or smaller ones may also be used. But 
the small screen is often to be preferred to a larger 
one, because with a screen larger than the part under 
scrutiny the eye becomes dazzled by the phosphor- 
escence of adjoining parts. Various phosphorescent 
bodies have been tried in the manufacture of screens, 
but the material which has finally asserted its superi- 
ority is the platino-cyanide of barium. This phos- 
phoresces with a greenish-yellow light. A little work 
in a dark room with a phosphorescent screen can 
be made extremely instructive. In this way one can 
learn how easy it is to produce distorted impressions 
when the object viewed is not in a plane with the 
surface of the screen. And from this one recognises 
how important it is in taking X ray photographs to 
arrange the careful adjustment of the tube, the patient, 
and the photographic plate, in their relations to each 

279. X ray photographs.— It has already been 
mentioned that Lenard early discovered the effect of 
X ray radiations upon photographic plates, even when 
the rays had passed through the sides of a cardboard 
box to reach the plates. In X ray practice photographs 
of the bones are taken by means of photographic plates 
enclosed in light tight envelopes of paper. The plate is 


usually enclosed in a yellow envelope, which again is 
enclosed in a black envelope. By this means the action of 
ordinary light upon the plate is prevented, but the passage 
of X rays to the plate remains quite possible. The plate 
enclosed in this way is laid upon a table or other support, 
and the limb is placed upon it. The tube is then ad- 
justed at a distance of a foot or eighteen inches above 
the limb, and the coil is set in action. The hand or limb 
must be kept quite still during the exposure, which may 
last from a few seconds up to many minutes, according 
to the efficiency of the apparatus and the density and 
thickness of the part to be photographed. As soon as 
the exposure is concluded, the coil is turned off, and 
the plate, still enclosed in its envelopes, is removed to a 
dark room for development, and development is carried 
out in the ordinary way, as in simple photography. 
Envelopes of the proper kind can be obtained from the 
makers of photographic materials. The photographic 
plates may be of any make or speed. Various kinds 
have been specially recommended by different writers, 
but there does not seem to be any conspicuous difference 
between one kind and another. It is better to choose 
one kind of plate and adhere to it, because in this way 
the peculiarities of the plate are the more quickly 
learned. Cadett's " Lightning " plates are good. In 
putting the plate into the envelopes a little care is 
needed in order that the film or sensitive side may face 
in the right direction. The plan is to put in the plate 
with its film side away from the flap or opening, and 
then to put the yellow envelope into the black envelope, 
with the plain sides in apposition. The side with the 
flap or opening of the envelope is then the side of the 
glass or non-sensitive side ; the other is the side of the 
film which must face the X rays. The operation must 



of course be done in a dark room. As with choice of 
plate, so with choice of developers ; it is best to make 
use of those with which one is best acquainted. A very 
simple and convenient developer is Rodinal. It has the 
advantages of easy preparation, of effective action, and 
it does not stain the fingers. As with X ray work 
the exposures are seldom very far removed from 
what may be called the minimum normal exposure, 
a simple developer of maximum strength can usually 
be employed without the risk of spoiling the plate in 
the process of developing, and whenever the exposure 
and the development are both carried out by the same 
person it is found that a time is soon reached when 
one may very closely assimilate time of exposure and 
strength of developer so as to give the best results. 
The question of skilful development belongs rather to 
photography than to medical electricity, and in many 
cases the plates are sent for development to professional 
photographers. But wherever the best results are 
desired it is recommended that development should be 
performed by the one who has exposed the plate. An 
over exposed plate may be known by a fulness of detail 
in the whole plate with a general blackness of the whole 
subject if development is fully carried out, while an 
under exposed plate shows very great contrasts with 
absence of detail in the shadows of the more opaque 
parts of the subject. An over exposed plate which has 
been developed for too short a time will be thin 
and lacking in density all over, although it may show 
details of structure in all parts of the subject. When 
many photographs have to be done, the time lost during 
prolonged exposures may become a serious item. But 
in ordinary private practice, where it is not likely 
that many plates will require to be done at the same 


time, it is better to give a full time exposure to the plate, 
in order to get all the detail which is possible. The 
question of the proper time to give to the different 
parts of the body is one which only practice can settle, 
for it depends upon the size of the coil, the energy with 
which it is driven, the quality of the tube that is being 
used for it, and the distance between the tube and the 
photographic plate. The nearer the tube is to the plate, 
the shorter need the exposure be. But, on the other 
hand, distortion is more evident in plates exposed with 
the tube very close than it is in plates exposed with a 
tube which is distant. For fine work, then, one will be 
content to have the tube at a distance of eighteen inches 
or two feet from the object, and to give a slightly longer 
exposure. The approximate times for a twelve inch 
coil may be set down somewhat as follows : — For the 
hand and wrist, fifteen to thirty seconds ; forearm, 
upper arm and elbow, one to two minutes ; shoulder 
and thorax, three to five minutes ; knee and thigh the 
same ; pelvis and abdomen up to six minutes. With 
smaller coils longer exposures will be necessary. But 
it must not be thought that a long exposure with a 
small coil will give equivalent results to those obtained 
from a short exposure with a large coil. The larger the 
coil the quicker may be the exposure, but in addition 
the sharper would be the picture. Sometimes one is 
annoyed by finding on development a general blurring 
and blackening of the photographic plate which other- 
wise shows little or no detail. This is a trouble met 
with, especially in the photography of thick parts of the 
body, like the abdomen and pelvis, with coils of poor 
power and long exposures. In photographing the trunk, 
then, it is best to make use of large coils, and to shorten 
the exposure to the minimum which will serve to give 


an image of the part desired. These parts, as a general 
rule, are the vertebrae, the kidneys (for renal stone), the 
pelvis and hip joints. All these subjects are extremely 
difficult to do nicely, even with the best coils, and long 
practice is needed in gauging the performance of the 
tube, and in adjusting the time of exposure to the bulk 
of the subject. When a tube has been found to have 
reached the degree of vacuum which just suits the coil 
used for these difficult parts, it is well to treasure such a 
tube, and to keep it only for these special subjects, 
using some other not so good for the easier parts, like 
the hands and feet, the forearms and legs. The 
tube should always be fixed so that the rays can fall 
perpendicularly from it upon the limb and the plate. 
Obliquity in the position of either the plate or the limb 
is likely to give that distortion which has been referred 
to in a preceding paragraph. A little study of these 
distortions as seen upon a phosphorescent screen held 
obliquely is the best method of learning what effects 
these distortions produce, and what is the best way to 
avoid them. 

280. The localisation of foreign bodies. — A diffi- 
culty which early showed itself in the localisation of 
foreign bodies by means of X ray photographs is the 
difficulty in determining the plane in the limb in which 
the foreign body is placed. How deep down is it ? is a 
question which will constantly be asked before any 
procedure for removal can be considered. Various 
plans for localisation have been devised. In this 
country the methods of Mr. Mackenzie Davidson are 
in almost universal use. 

The principle upon which Mr. Mackenzie Davidson's 
localiser depends is the displacement of the image of 
the foreign body on the photographic plate which is 


produced by a displacement in the position of the tube. 
Two exposures are given upon the same plate, the limb 
being perfectly still all the time, and a known displace- 
ment is given to the tube before the second exposure. 
Then, the distance of the tube from the plate being 
known, and the amount of the lateral displacement of 
the tube being known, a diagram can be constructed 
taking in these two factors and the measured displace- 
ment of the body as seen by its two images on the 
photographic plate ; and from this, by a simple calcu- 
lation, the distance of the foreign body from the sur- 
face of the photographic plate can be deduced. In 
practice the calculations are very much simplified by 
the use of the apparatus designed by Mr. Davidson. 
Two fine threads, starting from two points, which 
represent the two positions of the focus tube, are 
brought down to the two images of the foreign body 
which are seen upon the photographic negative. The 
point where the two threads cross in the air above the 
negative is the point at which the foreign body is 
situated. That, indeed, is the only point at which it 
can be, in order to throw the two images which it has 
thrown. By means of simple measuring scales supplied 
with the apparatus, the height or the depth of the body 
from the surface with which the plate was in contact is 
readily calculated. Its distance from a given point in 
the photograph, which is usually a line marked upon the 
surface of the patient at the time of the photograph, 
can also be measured quite easily. 

In very many cases the position of the foreign body 
can be estimated with considerable accuracy by the 
method of taking two photographs and viewing them 
in a stereoscope. For this the two photographs are 
taken not on the same plate, but on two separate plates 


but the tube is displaced for the second exposure, just 
as in the process just described. From the two nega- 
tives two prints are prepared, and these are viewed by 
means of a reflecting stereoscope. The binocular image 
thus obtained has a most remarkable effect in recon- 
structing to the observer's eye the entire part of the 
body in which the foreign body lies ; and it appears to 
stand out with all its roundness and thickness, and the 
foreign body also can be seen as it lies in the depth of 
the tissue in such a way as to give a very real picture 
of its actual position and depth from the surface. One 
or other of these methods, the method of measurement 
or the method of stereoscopic view can be adopted. 
The essential part for success in either of them is the 
exact adjustment and the exact measurement of the 
various distances ; namely, the distance of the tube 
from the plate, the distance through which the tube is 
displaced for the taking of the second photograph. 
The apparatus devised by Mackenzie Davidson renders 
all these details easy by means of dividing scales and 
sliding tube holders. 

281. Applications to diseases of the chest. — 
Although the detection and localisation of foreign bodies 
in the tissues is one of the most obvious of the applica- 
tions of X ray work in surgery, yet it is not by any means 
the only one. More important is the examination of 
fractures, dislocations, and other changes in connection 
with the bony skeleton. And perhaps more important 
still in the future may be the detection of changes in 
the soft tissues. The shadows cast upon photographic 
plates by X rays depend upon the different densities of 
the objects photographed. Thus, whereas in a photo- 
graph of a limb the contrast is between bone and the 
soft tissues, the detail being visible in the bone and 


the detail in the soft tissues being practically non- 
existent, yet in cases like the thorax, where the more 
dense heart is surrounded by the less dense lung, it 
becomes possible to obtain valuable photographs of the 
heart and of the lungs respectively. Changes in the 
size and shape of the heart, or of the aorta (aneurysm) 
can therefore be detected. In the lungs any changes 
tending to consolidation of the naturally spongy tissue 
can be detected for the same reason. Tumours, con- 
solidations — pneumonic and phthisical — and effusions 
into the pleura are all easily recognised in good X ray 
photographs of those parts. Its application to the 
study of early phthisis is perhaps one of the most 
promising of all the applications of X ray work to 
medicine. The chief work done in this country in 
that direction has been done in the electrical de- 
partment of St. Bartholomew's Hospital by Dr. Hugh 
Walsham.''' He has shown again and again that 
small tubercular consolidations which cannot be de- 
tected by the stethoscope can be easily and certainly 
revealed by X ray work. And the importance of this, 
when the early diagnosis of phthisis is in question, is 
enormous. This field, although at present hardly 
begun, is likely to progress considerably when it has 
been studied further. In the photographs of the chest, 
.as in those of the limbs, the combination of two pictures 
by means of the stereoscope is often of the greatest 
A^alue in enabling one to form an estimate of the actual 
position and depth from the surface of any tubercular 
consolidation or tubercular cavity ; for a cavity can be 
revealed by X rays just as well as a consolidation, 
.although for the opposite reason, namely, that whereas 
a consolidation is denser than the normal lung, a cavity 
is less dense. 

* Archives of the Rontgen Ray, May, 1900. 


282. Therapeutic uses of X rays. — In addition 
to the photographic appUcation of X rays for purposes 
of diagnosis, we have also to consider the therapeutic 
appHcations of the X rays themselves. Following upon 
the discovery that prolonged exposure to X rays pro- 
duced changes in the skin — the X ray burn — it has 
been found that careful graduation of this effect can be 
made to exercise a curative action upon certain skin 
diseases, and particularly upon lupus. The whole field 
of the application of X rays to diseases of the skin is 
one which has not yet greatly been worked at. In this 
country Miss Sharpe (see Archives of the Rontgen Ray) 
has detailed a number of experiences of her own 
of this kind. Abroad, the removal of superfluous hairs 
from the skin by exposure to the X rays has been 
elaborated by Professor Schiff, of Vienna, who has 
succeeded in so adjusting the degree of exposure as to 
cause a permanent shedding of the hairs without the 
destruction of the skin itself. The matter is one 
requiring great nicety of adjustment. The effect is 
one probably of damage to the superficial nerve end- 
ings, with consequent trophic changes which may affect 
only the hair bulbs, either temporarily or permanently^ 
or may exercise so severe an action as to cause per- 
manent destruction of the skin itself. The difficulty 
lies only in the adjustment of it. Whether these skin 
effects — the X ray burn and the others— are really due 
to the direct effect of the X rays themselves or not, is 
a little uncertain. As X ray tubes have been improved,, 
the number of recorded cases of X ray burn have 
decreased rather than increased. In the early days 
the conditions were tubes of comparatively low vacuum, 
long exposures, and tubes placed close to the patient. 
Those seem to be the conditions which favour the X 


ray burn ; and it has been believed that the effect on 
the skin is not so much an action of the X rays 
themselves, as of the electrical brush discharge taking 
place from the surface of the tube to the surface of 
the skin. 


1. Lists of Towns and Districts ivith Ccntinuons Current 



Alderley and Wilmslow 

Ashton-u nder-Lyne 













Bromley (Kent) 










Darwen (Lanes.) 





Fort William 









High Wycombe 








King's Lynn 









Maerdy (Glamorganshire) 











Ogmore Valley 






Richmond (Surrey) 



St. Austell 
















Charing Cross and Strand Co. 

Chelsea Co. 

Kensington and Knightsbridge 

Notting Hill Co. 
Smithfield Markets Co. 
St. James' and Pall Mall Co. 



St. Pancras (Vestry) 


Westminster Co. 





2. List of Towns and Districts with Alternating Current 
Sti'pply. The periodicity expresses the number of complete 
cycles (§71) of alternation per second. 



. 100 


• 50 


. 80 

Edinburgh (in part) . 

• 50 

Ayr . . . 

. 60 


. 100 



Fareham . 

. 125 

Bedford . 


Halifax . 

. 80 

Blackpool . 



. 100 



Harrogate . 

. 50 

Bournemouth . 


Hastings . 

• 100 

Bray (Ireland) . 


Huddersfield . 

. 100 



Keswick . 

. 100 



Killarney . 

. 100 




• 77 

Cardiff . 



. 100 




• 83 

Chagford . 


Leicester . 

• 50 

Chatham . 


Lynton and Lynmouth 

83, 100 




. 60 



Morley (Yorks.) 

. 60 

Coventry . 


Newcastle-on-Tyne . 

. 80 

Croydon . 


Newport . 

• 87 




• 50 



Plymouth . 

• 50 




. 100 



Prescot District 

. 100 



Reading . 

• 67 



Redditch . 
St. Helens 
Sheffield . 
Southpoit . 
South Shields 
Taunton . 



. 66 

Torquay . 

• 50 

. lOO 

Tunbridge Wells 

• 67 

. 60 

Wakefield . 

. 60 

• 75 

Wallasey . 

• 50 

. 80 

Watford . 

. 100 


West Ham 

• 50 

• 50 


. 100 

• 50 


. 100 


Yarmouth . 

• 83 

City of London 
Islington . 


100 London Electric Co. . S3 

50 Metropolitan Electric Co. 100 

go St. Luke's .... 100 

50 Clerkenwell . . . loa 

S3 Wandsworth . . . 100 

The voltage at the lamp terminals in dwelling houses is usuall}^ 
100, 105 or no volts. There is a growing tendency at present 
towards pressures which are double these figures, so that voltages 
of 200, &c., are not uncommon. Almost all makers of incandescent 
lamps mark the voltage for which they are made upon the glass of 
the bulb. An examination of the lamps used upon a circuit will 
therefore indicate the voltage of the circuit ; and often the candle 
power of the lamp and the watts (§ 39) consumed, may be learned in 
the same way. 

The periodicity (§ 76) of alternating currents must be known 
before a suitable transformer (§ 70) can be selected for use on such 

Plates I.— VI. 
The Motor Points. 


I. The Head and Neck. 

II. The Upper Limb (back). 

III. The Upper Limb (front). 

IV. The Thigh (front). 

V. The Thigh and Leg (back). 
VI. The Leg and Foot (outer side). 

Plates VII.— XI. 

The Cutaneous Nerves. 

VII. The Head and Neck. 

VIII. The Upper Limb (back). 

IX. The Upper Limb (front). 

X. The Lower Limb (front), 

XI. The Lower Limb (back). 



M. frontalis, 

Cjpper Iranch of facial, 

M. corrng. supercil. 

ir. orbic. palpelw. 
Nasal muscles | 


"H. orbicul. oris | 

Middle ira-nck of facial 

M. masseter 

IL levator menti . 

M. qnadr. menti ■ 

il. triang. menti- 

Hypoglossal n. 

Lovcer branch of facial 

M. platysma myoid. 

Hyoid muscles ■! 

M, omohyoideui 

Ant. tlioracic v. 
(M. pectoral.) 

Region of central 

Eegion of 3rcl frontrJ 
conv. and island 
of Keil (centre for 

IL temporalis 

Upper drancTi g 
in front of tl 

Facial n. (trunk) 
Fast, auricular n. 
Aliddle IrancTi of facial 
Lower branch of facial 
IT. splenius 
ai stemocleido- 

Spinal accessory n. 
11. levator angnli scapul. 
11. cncullaris 
Sorsalis scapulx 

Axillary n. 

Long thoracic n. (JL 
serrat.ant. maj.) 

;n, Sxpraclavicular point. Brachial plexus, 
(Erb's point. IT. deltoid., 
biceps, brachialis intern, 
rind fupin. long.) 

LL 2 


M. deltoM. 
(liinder part) 

Radial Nerve 

M. brachial, intern. 

M. supinator long. 
M. radial, est. long. 
M. radial, est. brev. 

M. extensor digit, 

M. extensor indiois 

M. abductor poUic. long. 
M. extensor pollic, brev. 

M. inteross. dorsal. I. 


M, triceps (caput 

) M. triceps (caput 
]■ extern.) 


M. ulnar, extern. 
M. supinat. brev. 

M. extens. digiti minim. 
M. extens. indicis 

M. extens. poll. long. 

M. abduct, digit, min. 

M. inteross. dorsal, 
ni. et TV. 


M. triceps (long head) 

M, triceps (inner head) 
Ulimr n, 

M. flexor caxpi ulnaris 

M. flex, digitor. commun 

M. flex, digitor. sublim. 

31. flex, digit, subl. (digit, 
indicis et minimi) 

M. palmaris brev. 

M. abductor digiti min. 

M. flexor digit, min. 

M. opponens digit, min. 

Mm. lumbricaJes -j 

M. biceps bracliii 

SL abductor pollic. brcT. 
M. opponens pollicis 

M. flex. poll. brev. 

M. adductor pollic. brev. 


AI, adductor magnus 
M. adduct. longus 

tensor f as'cia3 lata; 

IT. quadriceps femoris 
(common point) 

M. rectus femoris 

M. vastus externua 

M. vastus intemus 


M. biceps, fern. (cap. 

M. biceps fern. (cap. 

M. gastrocnem. (cap, 

M. Eoleus 

M. flexor hallucis longus 

M. gluteus masimus 

•M. adductor magnus 
M. semitcndinostis 
M, senumembranosus 

Tibial n. 

M. gastrocnem. (cap. int.) 
M. soleus 

M. flexor digitor. comm. 

Tibial n. 


IL tibiaL antic, 

ISL eztens. digit, comm. 

M. peroneus breyis 

M. extensor hallncis 

Httuinterossei doTsales 

Peroneal n. 

M. gastiocnem. estem. 
IT. peroneus longus 

M. flexor hallucis long. 

M. extens. digit, coram, 

M. abductor digiti min. 


Great occipital —" i 

Small occipital 
(cervical plexus) 

Great auricular 

(cervical plexus)'—- 

5th. supra-orbital branch 
5th. auriculo temporal branch 

-^■^-J-Sth. infra-orbital branch 

5th, inferior dental branch 

Superficial cervical 
(cervical plexus) 


Intercostal humeral 

Lesser inter, cutaneoiis 

Internal cutaneous 




Musculo-spiral int. cut 


Musculo-spiral external 
cutaneous branch 

—-^c:-\—- Radial 


Supra-clavicular nerves 


Musculo-spiral external 
cutaneous branch 



Intercostal humeral 

Lesser int. cutaneous 

Internal cutaneous 



Genito-crural— ' 

External cutaneous 

Anterior crural middle 
cutaneous branch 

External popliteal 

External saphenous 


Anterior crural 
(int. cutaneous branch) 

Anterior crural 
(long saphenous branch) 

Anterior tibial 


Inferior gluteal 

Anterior crural, internal 
cutaneous branch 

Post tibial 

External cutaneous 

SS} sciatic 

Ext. popliteal 

Ext. saphenous 



v«Xvvtwi^ (Ut^^A.C'cU^Wi.) 


A. C. C. (Anodal Closing Contrac- 
tion), 203 
Accumulators, 67 
charging, 94 
for cautery, 473 
for surgical lamps, 480 
lithanode, 70 
Acne, 416 

Action of points, 21 
Alcoholic neuritis, 362 
Alternating current, 98, 120 
Amalgam, electrical, 11 
Amalgamation of zinc, 78 
Amenorrhoea, 426 
Ammeter, 147 
Ampere, 37 
Ampere hour, 37 
-Ansemia, 308, 427 
Anaesthesia, 402 
estimation of, 255 
treatment of, 402 
Analgesia, 211 
Anelectrotonus, 201 
Aneurysm, 448 
Angioma (Nsevus), 439 
Anode, 40 

effects of, 200, 203, 212, 263, 268 
Aphasia, 318 
Aphonia, 322 
Apostoli, 458 
Arm-bath, 298, 312 
Arrangement of cells, 52 
Arsenical neuritis, 361 
Arsonval, 184, 262 
Arthritis, 408 

rheumatoid, 300 
Artificial respiration, electricity in, 

Ascending currents, 201 
Ascites, 414 

Ataxy, locomotor, 305, 353 
Atrophy, progressive muscular, 305 

Auditory nerve reactions, 212, 258 

treatment, 404 

Bath electric, 282 
Batteries, 48 

care of, 77 

choice of, 74 

electromotive force of, 48 

table of, 73 

testing of, 148 
Battery, bichromate, 56 

Bunsen, 58 

chloride of silver, 64 

Daniell, 57 

dry, 63 

Grove, 58 

Hellesen, 63 

Lalande, 64 

Latimer Clarke, 65 

Leclanche, 59 

lithanode, 70 

oxide of copper, 64 

secondary, 67 

Smee's, 55 

Stohrer's, 66 

sulphate of mercury, 65 
Bergonie, on facial neuralgia, 398 

rheostat, 347 
Bichromate solution, 56 
Bladder, affections of, 418 
Bottini's prostatic cautery, 471 
Brachial plexus, 355 
! injury of, 383 



Brachial plexus, neuralgia of, 399 
Brain, diseases of, 314 

treatment of, 316 
Breeze, electric, 170 
Bruce Clarke on stricture, 450 

prostate, 471 
Brush discharge, 170 

electrode, 128 
Bunsen's battery, 58 

Cancer, electrolysis in, 467 
Capacity, electric, 22 

specific inductive, 24 

unit of, 37 
Capriati, 403, 215 

Cardew, Dr., on exophthalmos, 332 
Cataphoresis, 217 
Cathode (see Kathode), 40 
Cautery, accumulator for, 473 

battery for, 472 

instruments, 468 

rheostat for, 474 
Cells (see Battery) 

in parallel, 52 

in series, 52 
Central galvanisation, 276 
Cerebral disease, 314 
C. G. S. units, 36 
Charge, distribution of, 21 
Charging an accumulator, 94 
Chloride of silver cell, 64 
Chlorosis, 308 
Choice of current, 264 

of pole, 268 
Chorea, 319 
Circuit, galvanic, 26 

magnetic, 29 
Circumflex nerve, injury of, 379 
Club-foot, 349 
Coils, induction, 104 

medical, plan of, 108 

primary, 106 

regulation of, loS 

secondary, 113 
Collectors, double, 132 

single, 131 
Commutator, 135 
Compass needle, 27 
Condensers, 23 
Conducting wires, 124 
Conduction, 13, 33 

Conduction in the body, 191 
Conductors, 13 

for electro-statical treatment, 
163, 165 
Constipation, 423 
Contact breaker, io5 

electromotive force, 25 
Continuous current, 264 
Contraction, laws of, in man, 203 
Contracted joints, 411 
Contractures, 410 
Colomb, 37 
Crutch paralysis, 390 
Current, alternating, 8g, 98, 120 

collector, 131 

continuous, 264 

direct, 264 

density of, 195 

diffusion of, 195 

direction of, 201 

effects of, 261 

electric lighting, 88 

heating effects of, 42, 219 

induced, 44, 104 

measurement of (see Galvano- 
meter), 142 

of action, 199 

primary, 106 

sinusoidal, 120, 266 

secondary, 106 

strength of, 266 

unit of, 37 
Curves of current, 120 
Cystoscope, 481 

Daniell's cell, 57 
D'Arsonval, 184, 262 
j Death from electricity, 217 

test for, 430 
Degeneration, reaction of, 241 
De Haen, 2 
Deltoid paralysis, 379 

rheumatism, 183, 399 
Density of current, 195 

electric, 21 
Depolarizers, 54 
Diagnosis, 225 

chart, 236 

galvanometer in, 239 
Dial collectors, 131 
Diaphragm, stimulation of, 429 



Dielectric constant, 24 
Diffusion of current, 195 
Diphtheritic paralysis, 367 
Direction of current, 201 
Dislocations, paralysis from, 356, 

Disorders of hearing, 404 

sexual, 425 

uterine, 425 
Dry bath, static, 168 

cells, 63 
Duchenne, 3 

on infantile paralysis, 349 

on interrupted currents, in 

on lead palsy, 360 

on progressive muscular atrophy, 

on muscles of the leg, 349 
Dynamo-machine, 81 
Dynamo-motor, 102 
Dysmenorrhcea, 178 

Early writers, 2 

Ears, subjective noises in, 405 

Effect of -pole, 268 

Effects of electrical treatment, 261 

Electric baths, 282 

current for, 289 

electrodes for, 284 , 

hot air or vapour, 297 

resistance of, 287 

temperature of, 284 

uses of, 282 
Electric breeze, 170 

charging, 168 

density, 21 

fishes, 220 

hand, 273 

electric light currents, 88 
Electrical frictions, 173 

machines, 158 
Holtz, 152 
Wimshurst, 155 

organs, 220 
Electricity as a test of death, 430 

first used in hospitals, 3 

origin of word, i 

physiological effects of, 191 

positive and negative, 10 

static, 151 
Electrics, i 

Electrodes, 125, 128 

aural, 259 

bath, 285 

cutaneous, 256 

electrostatic, 165 

hand, 273 

naevus, 443 

perineal, 422 

rectal, 424 

standard sizes, 127 

urethral, 421 

uterine, 463 

wire brush, 128 
Electrolysis, 38, 432 

in living tissues, 433 

laws of, 40 
Electrolyte, 40 
Electro-magnet, 82 
Electro-magnetic induction, 44 
Electrometer, 12 
Electromotive force, 16 

induced, 45 

of batteries, 48, 73 

unit of, 36 
Electroscope, 12 
Electrostatics, 151 
Electrotonus, 200 
Enuresis, 420 
Epilation, 436 
Epilepsy, 319 

Equivalents, electro-chemical, 41 
Erb's paralysis, 385 
Eustachian obstruction, 455 
Examination of patients, 234 
Excitability, alterations in, 237 
Exophthalmic goitre, 331 
Extra current, 106 
Eyelashes, ingrowing, 438 

Facial neuralgia, 397 

paralysis, 369 

spasm, 325, 326 
Farad, 37 
Faraday, 104 
Faradic currents, 44, see Induction 

coil, 104 
Faradisation general, 272 
Farrier, Dr., on special nerve 

roots, 232 
Fibro-myoma, 458 
Fluid theory, 9 




Foetation, extra-uterine, 465 
Frictions, electrical, 173 

Galactagogue effects, 428 
Galvanic treatment of ulcers, 416 
Galvanisation, central, 276 
Galvano-cautery, 468 
Galvano-faradisation, 275 
Galvanometer, 30, 142 

Edelmann's, 145 

for induction coil currents, 117 

horizontal, 143 

in diagnosis, 235 

shunt for, 146 

tangent, 32 
General faradisation, 272 
Goitre, exophthalmic, 331 
Gonorrhoeal rheumatism, 302 
Gout, 302 
Graphite rheostat, 141 

Hairs, removal of, 436 
Hand electrode, 273 
Headache, 172, 181 
Heart stimulation of, 208, 429 
Heating effects, 42, 219 
Hemiplegia, 317 
Herpetic neuralgia, 399 
Herringham, Dr., on brachial 

plexus, 233 
High frequency currents, 183 
High potential currents, 183 
Hollow club-foot, 350, 395 
Holtz machine, 152, 160 
Human body, resistance of, 191 
Hypochondriasis, 323 
Hypothesis of fluids, 9 
Hysteria, 321 

Incandescent lamps, 44, 478 
Incontinence of urine, 420 
Induction coil, 104 

electro-magnetic, 44 

electro-static, 13 
Infantile paralysis, 340 
Influence machines, 152 
Influenza, sequelae of, 306, 367 
Injuries of nerves, 354 
Insomnia, 178, 276, 324 
Insulators, 13 
Internal resistance, 50 

Interossei, paralysis of, 350, 392 
Interruptor, automatic, io5 
Ions, 38, 433 

Jallabert, 2 

Joint affections, 408 

Kathelectrotonus, 201 
Kathode, 40 

effects of, 269 
K.C.C. (kathodal closure contrac- 

tion), 203 

Labile method, 270 

Lalande cell, 64 

Lamp, abdominal, 485 

Lamps, 478 

Law of contractions, 203 

Lead palsy, 307, 359 

Leclanche cell, 59 

Leduc, 316, 411 

Legal ohm, 36 

Lethal effects of electricity, 217 

Leyden jar, 24, 174, 184 

Lines of force, magnetic, 29 

Lithanode, 70 

Locomotor ataxy, 353 

Lumbago, 183 

Machines, electrical, 151 

Magnetic field, 28, 82 
lines of force, 28 
needle, 27 

Magnetism, physiological effects 
of, 221 

Magneto-machine, 82 

Mammary gland, stimulation of, 

Measurement of current [sec Gal- 

Megohm, 37 

Mental diseases, 308 

Metallic poisoning, 306 
tremors, 307 

Metals, resistance of, 33 

Microfarad, 37 

Migraine, 333 

Milk, secretion of, 428 

Milliampere, 37 

Moles, treatment of, 438 

Morton, Dr., 217 



Motor point of Erb, 231 
Motor points, 228 
Muscle, excitation of, 198 

heart, 208 

reactions of, 203 

unstriped, 207 
Myalgia, 417 
Myelitis, 305, 334 

Naevus, 439 

Negative variation, 200 

Nerves, injuries of, 354 

testing of, 225 
Nervous deafness, 404 
Neuralgia, 172, 395 
Neurasthenia, 323 
Neuritis, 358 
Nocturnal incontinence of urine, 


Obstetric practice, electricity in, 

425, 427, 458 
Ocular muscles, paralysis of, 368 
Oersted's experiment, 28 
Ohm, 36 
Ohm's law, 34 

applications of, 35 
Ophthalmoscope, 479 
Optic nerve atrophy, 403 
Osmosis, electrolytic, 216 

Pain, relief of, 172, 181, 266 
Panelectroscope, 484 
Parallel, batteries in, 52 
Paralysis after diphtheria, 367 

infantile, 340 

treatment of, 335 
Partial RD, 246 
Parturition, electricity in, 427 
Pes cavus, 350, 395 
Physiological effects of current, 

191, 203 
Plates of a battery, 27 
Plexus, brachial, injury of, 383, 

brachial, neuralgia of, 399 
Plumbism, 359 
Points, action of, 21, 167 
Polarisation, 53 
Pole tester, 80 
Poles, choice of^ 268 

Poles, North and South, 28 
positive and negative, 9, 27 

Port wine mark, 448 

Positive charge, effects of, 168 

Potential, definition of, 16 
slope of, 92 

Pressure paralysis, 389, 390 

Primary coil, 106 

Progressive muscular atrophy, 350 

Quantity, electricity, 15 
unit of, 16, 37 

Raynaud's disease, 311 
Reaction of degeneration, 241 

causes of, 247 

course of, 243 

diagnostic value, 249 

partial, 246 

prognosis in, 248 
Reactions, anomalous, 255 

auditory, 258 

in infantile paralysis, 343 

morbid changes in, 237 

sensory, 255 
Reflex neuralgias, 395 
Refreshing action, 214 
Regulation of current, 136 
Remak, 408 

Removal of superfluous hairs, 436 
Resistance, 32 

box, 138 

coils, 138 

internal, 50 

measurement of, 137 

of an electrolyte, 41 

of bath, 287 

of batteries, 71 

of carbon, 34 

lamps, 92 

of the body, 191 

specific, 33 

unit of, 36 
Reverser, 135 
Rheumatism, 410 
Rheumatoid arthritis, 300 
Rickets, 308 
Roots of spinal nerves, 232 

Sciatica, 400 

Scleroses of spinal cord, 305, 343 
MM 2 



Secondary coil, io6 

Secretion of milk, 428 

Self-induction, 46 

Self treatment by patients, 279 

Sensations electrical, 208 

Sensory nerves, 208 

Series, batteries in, 52 

Serratus magnus, 375 

Sexual disorders, 425 

Shunt circuits, 92 

Shunts, galvanometer, 146 

Skin, diseases of, 416 

Skin, resistance of, igi 

Sledge coil, 108 

Sleep paralysis, 389 

Smee's battery, 55 

Sparks, treatment by, 172 

Spasmodic affections, 324 

Spinal cord, diseases of, 324 

nerve roots, relation to muscles, 
Sprains, 408 
Stabile method, 270 
Standard cell, Clark's, 65 
Static induction, 176 
Statical apparatus, 163 

treatment, 168 
in chorea, 319 
Steavenson, Dr. W. E., on stric- 
ture, 451 

and Mr. Cumberbatch on Eus- 
tachian obstruction, 455 

and Mr. Jessop on lachrymal 
obstruction, 457 
Stohrer's battery, 66 
Stricture of Eustachian tube, 455 

of lachrymal canal, 457 

of oesophagus, 455 

of urethra, 451 
Subaural galvanisation, 279 
Supra-clavicular point of Erb, 231 
Syncope, electricity in, 429 

Tabes dorsalis, 353 
Tetany, 330 

Therapeutics, general, 261 
Tic douloureux, 397 
Tinnitus aurium, 405 

electrode for, 259 
Torticollis, 325 
Toxic paralyses, 359 
Transformers, 98 
Trapezius, paralysis of, 371 
Traumatic paralysis, 354 
Treatment, duration, 268 

effects of, 261 

methods of, 264 
Tremors, 224 
Trichiasis, 438 
Trophic effects, 261, 338 
Two fluid cell, 55 

theory, 9 

Ulcers, healing of, 416 
Unit of current, 37 
Units C. G. S., 36 

practical, 36 
Urethra, stricture of, 450 
Urinary organs, disease of, 418 
Uterus, fibroids of, 458 

Vasomotor effects, 262, 264 
Volt, 37 

Voltaic cell, simple, 27 
Voltameter, 149 
Voltmeter, 147 

Watt, 43 

Wimshurst machine, 155, 158 

Women, diseases of, 425 

Writer's cramp, 327 

Wry neck, 325 

X rays, 488 





(Established 1844). 

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Heath Professor of Comparative Pathology in the University of Dublin; 
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*-^ Myxcedema and Cretinism. With numerous Illustra- 
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^ Second Edition, thoroughly revised, with two coloured 
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•*• and Treatment. Second Edition, enlarged, with six Plates 
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Wew and Recent Works published by 


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*• NAL. A Manual of Diagnosis for Students and Practi- 

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H. K. Lewis, 136 Gower Street, London. 3 

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-*■ DENTS, Required at the First Examination of the 

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16 H. K. Lewis's Publications. 

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